Estudos citol��gicos em Hem��oteros da fam��lia Coreidae

A more or less detailed study of the spermatogenesis in six species of Hemiptera belonging to the Coreid Family is made in the present paper. The species studied and their respective chromosome numbers were: 1) Diactor bilineatus (Fabr.) : spermatogonia with 20 + X, primary spermatocytes with 10 + X, X dividing equationaliv in the first division and passing undivided to one pole in the second. 2) Lcptoglossus gonagra (Fabr.) : spermatogonia with 20 + X, primary spermatocytes with 10 + X, X dividing equationally in the first division and passing undivided to one pole in the second. 3) Phthia picta (Drury) : spermatogonia with 20 + X, primary spermatocytes with 10 + X, X dividing equationally in the first division and passing undivided to one pole in the second. 4) Anisocelis foliacea Fabr. : spermatogonia with 26 + X fthe highest mumber hitherto known in the Family), primary .spermatocytes with 13 + X, X dividing equationally in the first division an passing undivided to one pole in the second. 5) Pachylis pharaonis (Herbtst) : spermatogonia with 16 + X, primary spermatocytes with 8 + X. Behaviour of the heteroehromosome not referred. 6) Pachylis laticornis (Fabr.) : spermatogonia with 14 + X, primary spermatocytes with 7 + X, X passing undivided to one pole in the first division and therefore secondary spermatocytes with 7 + X and 7 chromosomes. General results and conclusions a) Pairing modus of the chromosomes (Telosynapsis or Farasynapsis ?) - In several species of the Coreld bugs the history of the chromosomes from the diffuse stage till diakinesis cannot be follewed in detail due specially to the fact that lhe bivalents, as soon as they begin to be individually distinct they appear as irregular and extremely lax chromatic areas, which through an obscure process give rise to the diakinesis and then to the metaphase chomosomes. Fortunately I was able to analyse the genesis of the cross-shaped chromosomes, becoming thus convinced that even in the less favorable cases like that of Phthia, in which the crosses develop from four small condensation areas of the diffuse chromosomes, nothing in the process permit to interpret the final results as being due to a previous telosynaptic pairing. In the case of long bivalents formed by two parallel strands intimately united at both endsegments and more or less widely open in the middle (Leptoglossus, Pachylis), I could see that the lateral arms of the crosses originate from condensation centers created by a torsion or bending in the unpaired parts of the chromosomes In the relatively short bivalents the lateral branches of the cross are formed in the middle but in the long ones, whose median opening is sometimes considerable, two asymetrical branches or even two independent crosses may develop in the same pair. These observations put away the idea of an end-to-end pairing of the chromosomes, since if it had occured the lateral arms of the crosses would always be symetrical and median and never more than two. The direct observation of a side- toside pairing of the chromosomal threads at synizesis, is in foil agreement with the complete lack of evidence in favour of telosynapsis. b) Anaphasic bridges and interzonal connections - The chromosomes as they separate from each other in anaphase they remain connected by means of two lateral strands corresponding to the unpaired segmenas observed in the bivalents at the stages preceding metaphase. In the early anaphase the chromosomes again reproduce the form they had in late diafcinesis. The connecting threads which may be thick and intensely coloured are generally curved and sometimes unequal in lenght, one being much longer than the other and forming a loop outwardly. This fact points to a continuous flow of chromosomal substance independently from both chromosomes of the pair rather than to a mechanical stretching of a sticky substance. At the end of anaphase almost all the material which formed the bridges is reduced to two small cones from whose vertices a very fine and pale fibril takes its origin. The interzonal fibres, therefore, may be considered as the remnant of the anaphasic bridges. Abnormal behaviour of the anaphase chromosomes showed to be useful in aiding the interpretation of normal aspects. It has been suggested by Schrader (1944) "that the interzonal is nothing more than a sticky coating of the chromosome which is stretched like mucilage between the daughter chromosomes as they move further and further apart". The paired chromosomes being enclosed in a commom sheath, as they separate they give origin to a tube which becomes more and more stretched. Later the walls of the tube collapse forming in this manner an interzonal element. My observations, however, do not confirm Schrader's tubular theory of interzonal connections. In the aspects seen at anaphase of the primary spermatocytes and described in this paper as chromosomal bridges nothing suggests a tubular structure. There is no doubt that the chromosomes are here connected by two independent strands in the first division of the spermatocytes and by a single one in the second. The manner in which the chromosomes separate supports the idea of transverse divion, leaving little place for another interpretation. c) Ptafanoeomc and chromatoid bodies - The colourabtlity of the plasmosome in Diactor and Anisocelis showed to be highly variable. In the latter species, one may find in the same cyst nuclei provided with two intensely coloured bodies, the larger of which being the plasmosome, sided by those in which only the heterochromosome took the colour. In the former one the plasmosome strongly coloured seen in the primary metaphase may easily be taken for a supernumerary chromosome. At anaphase this body stays motionless in the equator of the cell while the chromosomes are moving toward the poles. There, when intensely coloured ,it may be confused with the heterochromosome of the secondary spermatocytes, which frequently occupies identical position in the corresponding phase, thus causing missinterpretation. In its place the plasmosome may divide into two equal parts or pass undivided to one cell in whose cytoplasm it breaks down giving rise to a few corpuscles of unequal sizes. In Pachylis pharaonis, as soon as the nuclear membrane breate down, the plasmosome migrates to a place in the periphery of the cell (primary spermatocyte), forming there a large chromatoid body. This body is never found in the cytoplasm prior to the dissolution of the nuclear membrane. It is certain that chromatoid bodies of different origin do exist. Here, however, we are dealing, undoubtedly, with true plasmosomes. d) Movement of the heterochromosome - The heterochromosome in the metaphase of the secondary spermatocytes may occupy the most different places. At the time the autosomes prient themselves in the equatorial plane it may be found some distance apart in this plane or in any other plane and even in the subpolar and polar regions. It remains in its place during anaphase. Therefore, it may appear at the same level with the components of one of the anaphase plates (synchronism), between both plates (succession) or between one plate and tbe pole (precession), what depends upon the moment the cell was fixed. This does not mean that the heterochromosome sometimes moves as quickly as the autosomes, sometimes more rapidly and sometimes less. It implies, on the contrary, that, being anywhere in the cell, the heterochromosome m he attained and passed by the autosomes. In spite of being almost motionless the heterochromosome finishes by being enclosed in one of the resulting nuclei. Consequently, it does move rapidly toward the group formed by the autosomes a little before anaphase is ended. This may be understood assuming that the heterochromosome, which do not divide, having almost inactive kinetochore cannot orient itself, giving from wherever it stays, only a weak response to the polar influences. When in the equator it probably do not perform any movement in virtue of receiving equal solicitation from both poles. When in any other plane, despite the greater influence of the nearer pole, the influence of the opposite pole would permit only so a slow movement that the autosomes would soon reach it and then leave it behind. It is only when the cell begins to divide that the heterochromosome, passing to one of the daughter cells scapes the influence of the other and thence goes quickly to join the autosomes, being enclosed with them in the nucleus formed there. The exceptions observed by BORING (1907) together with ; the facts described here must represent the normal behavior of the heterocromosome of the Hemiptera, the greater frequency of succession being the consequence of the more frequent localization of the heterochromosome in the equatorial plane or in its near and of the anaphase rapidity. Due to its position in metaphase the heterochromosome in early anaphase may be found in precession. In late anaphase, oh the contrary ,it appears almost always in succession. This is attributed to the fact of the heterochromosome being ordinairily localized outside the spindle area it leaves the way free to the anaphasic plate moving toward the pole. Moreover, the heterochromosome being a round element approximately of the size of the autosomes, which are equally round or a little longer in the direction of the movement, it can be passed by the autosomes even when it stands in the area of the spindle, specially if it is not too far from the equatorial plane. e) The kinetochore - This question has been fully discussed in another paper (PIZA 1943a). The facts treated here point to the conclusion that the chromosomes of the Coreidae, like those of Tityus bahiensis, are provided with a kinetochore at each end, as was already admitted by the present writer with regard to the heterochromosome of Protenor. Indeed, taking ipr granted the facts presented in this paper, other cannot be the interpretation. However, the reasons by which the chromosomes of the species studied here do not orient themselves at metaphase of the first division in the same way as the heterochromosome of Protenor, that is, with the major axis parallelly to the equatorial plane, are claiming for explanation. But, admiting that the proximity of the kinetochores at the ends of chromosomes which do not separate until the second division making them respond to the poles as if they were a single kinetochore ,the explanation follows. (See PIZA 1943a). The median opening of the diplonemas when they are going to the diffuse stage as well as the reappearance of the bivalents always united at the end-segments and open in the middle is in full agreement with the existence of two terminal kinetochores. The same can be said with regard to the bivalents which join their extremities to form a ring.

II - Contribui����o para o estudo biol��gico e ecol��gico das podostemonaceae do salto de Piracicaba

Resumindo as observa����es feitas sobre a biologia e a ecologia das esp��cies Apinagia Accorsii Toledo e Mniopsis Glazioviana Warmg., Podostemonaceae que vivem incrustadas ��s rochas diab��sicas do Salto de Piracicaba, durante os anos de 1943, 1944 e 1945, cheguei ��s conclus��es seguintes: a) Com o in��cio do per��odo de enchente do Salto de Piracicaba, vari��vel de ano para ano, mas que, no geral, come��a com as primeiras chuvas de outubro e se prolonga at�� fins de mar��o, processa-se o desenvolvimento vegetativo das Podostemonaceae, com a forma����o de estolhos (Fig. 15-B) dotados de gemas produtoras de novos rizomas (Fig. 16-A, C, D, E) e regenera����o dos rizomas primitivos (Fig. 15-B), quando em determinadas condi����es, em Apinagia Accorsii; ra��zes hemicilindricas com produ����es fali��ceas, dispostas aos pares. (Fig. 19-A,B, C,D,E,F,G,H), provenientes de gemas, em Mniops's Glazioviana, Demais, em ambas as esp��cies realiza-se ainda a germina����o das sementes nos seguintes substratos : placentas, c��psulas e pedicelos de frutos (Figs. 16, 17, 18 e 20), res��duos org��nicos de v��rias proced��ncias, inclusive os provenientes das pr��prias Podostemonaceae, que se acumulam em quantidade apreci��vel entre as plantas e sobre as rochas, etc. A Ap-nagia Accorsii, al��m desses meios, conta ainda com os res��duos rizom��ticos, com os caules e mesmo com a superficies dos rizomas (Fig. 21-H). A massa rizom��tica constitui excelente meio para a reten����o germina����o das sementes. b) A deisc��ncia dos frutos d��-se ao contacto do ar seco. As sementes podem fixar-se aos substratos citados, devido �� transforma����o do tegumento externo em mucilagem. c) Dentre os substratos para a germina����o das sementes, o mais importante e mesmo decisivo, em determinadas circunst��ncias, para a garantia da esp��cie no habitat, �� o fruto. Ap��s a deisc��ncia, algumas sementes podem colar-se ��s paredes internas da c��psula e aos pedicelos, gra��as �� mucilagem do tegumento externo, ao passo que outras permanecem s��bre a placenta. d) Os "seedlings" n��o apresentam raiz principal. Todavia, �� volta de toda a extremidade do hipoc��tilo, produz-se enorme quantidade de p��los radiculares, cuja principal fun����o �� servir de ��rg��os de fixa����o. A incrusta����o das plantas ao substrato �� feita por meio de p��los radiculares, ou, mais freq��entemente, por "haptera". Segundo WILLIS (1915), "os "haptera" s��o ��rg��os adesivos especiais, provavelmente de natureza radicular, que aparecem como protuber��ncia ex��genas da raiz ou do caule e se curvam para a rocha, onde se fixam e se achatam, segregando uma subst��ncia viscosa". e) Os "seedlings", que se desenvolvem sobre as c��psulas, pedicelos, etc., encontrando condi����es ecol��gicas favor��veis, transformam-se rapidamente em plantas jovens; os novos rizomas j�� come��am a produzir caules e em tudo se assemelham aos rizomas provenientes dos estolhos. �� o que se observa no habitat, por ocasi��o da germina����o das sementes. f) As transfer��ncia das plantinhas, que so desenvolvem nos substratos citados para a superf��cie da rocha, realiza-se quando elas alcan��arem o peso suficiente para curvar o pedicelo do fruto. (Figs. 17 e 18), promovendo, assim, o contacto da c��psula com a rocha. Da�� por diante, o novo rizoma vai aderindo ao substrato natural, atrav��s da produ����o dos ��rg��os especiais de fixa����o, isto ��, p��los radiculares e "haptera". O mecanismo da Devido a um pequeno engano na feitura dos clich��s, os aumentos das figuras 15, 16, 19 e 20, constantes da legenda, passar��o a ser respectivamente :- 1,9 - 1,65 - 2,3 e 2,9. 39 transfer��ncia das plantas jovens que, inicialmente, se desenvolvem sobre c��psulas, pedicelos, etc., para o substrato definitivo - a rocha - foi verificado, freq��entes vezes, em farto material que incluia v��rios est��gios de desenvolvimento vegetativo (Figs. 16, 17, 18, 20). g) As c��psulas, compreendendo, al��m da placenta (em certos casos), as paredes internas e externas, e os pedicelos dos frutos de ambas as esp��cies estudadas constituem excelentes e importantes meios para a fixa����o das sementes. Ap��s os longos periodos de seca, quando toda a parte vegetativa se destroi, tornam-se os ��nicos substratos apropriados para o fen��meno da germina����o. h) Iniciada a fase vegetativa e, �� medida que progride a submers��o das plantas, acentuam-se, cada vez mais, o crescimento e o desenvolvimento. �� precisamente durante a ��poca de submers��o que as Podostemonaceae encontram o ambiente mais adequado ao seus desenvolvimento vegetativo, alcan��ando, ao mesmo tempo, a m��xima distribui����o local, mormente a esp��cie Apinagia Accorsii Toledo, que chega a cobrir todas as rochas situadas da regi��o frontal da cachoeira. i) O decl��nio das ��guas come��a, aproximadamente, em fins de mar��o, com as ��ltimas chuvas. Pode-se, ent��o, avaliar a extens��o do desenvolvimento vegetativo que as plantas alcan��aram, durante a fase de enchente. O n��vel da correnteza vai, da�� por diante, baixando gradativamente, at�� fins de setembro, quando atinge o m��nimo, ocasi��o em que o Salto se apresenta com o m��ximo de rochas expostas. j) Durante todo o per��odo de vazante, que �� vari��vel e dependente do regime de chuvas que vigorar, as plantas v��o paulatinamente emergindo, ao mesmo tempo que cessa o desenvol-vimnto vegetativo, para entrar em atividade o ciclo floral. Antes, por��m, os caules de Apinagia que estiveram submetidos ��s fortes vibr��a����es da correnteza se destacam (Fig. 21-A,C,F,G, H,I). Todavia, as plantas, que se desenvolveram em regi��es de correnteza mais branda, n��o chegam a perder os seus caules. k) As gemas flor��feras, �� medida que v��o emergindo, desabrochan!. As flores desenvolvem-se rapidamente; a poliniza����o que �� direta efetua-se em plena atmosfera, quando as anteras enxutas e suficientemente dessecadas sofrem a deisc��ncia, libertando o p��len. Realizada a fecunda����o, as sementes atingem depressa a maturidade. Como todo o desenvolvimento compreendido entre o desabrochar das gemas e a frutifica����o se processa fora da ��gua e como a exposi����o das plantas �� gradativa, em virtude do lento decl��nio das ��guas, compreende-se que no Salto existam, a um tempo, todos os est��gios do ciclo vegetativo ao lado de todas as fases do desenvolvimento floral. l) Os rizomas, em contacto com o ar e sob a a����o solar, dessecam-se, transformando-se em placas duras, fortemente inscrustadas ��s rochas. Mas, se durante a desseca����o forem umidecidos, de quando em quando, passam a constituir excelente meio para a reten����o e germina����o das sementes. m) No per��odo seguinte de enchente e vazante, repetem-se, para as esp��cies estudadas, todas as fases do desenvolvimento vegetativo e floral, assinaladas nesta contribui����o.

Dissecando o GEN

In thee present paper the classical concept of the corpuscular gene is dissected out in order to show the inconsistency of some genetical and cytological explanations based on it. The author begins by asking how do the genes perform their specific functions. Genetists say that colour in plants is sometimes due to the presence in the cytoplam of epidermal cells of an organic complex belonging to the anthocyanins and that this complex is produced by genes. The author then asks how can a gene produce an anthocyanin ? In accordance to Haldane's view the first product of a gene may be a free copy of the gene itself which is abandoned to the nucleus and then to the cytoplasm where it enters into reaction with other gene products. If, thus, the different substances which react in the cell for preparing the characters of the organism are copies of the genes then the chromosome must be very extravagant a thing : chain of the most diverse and heterogeneous substances (the genes) like agglutinins, precipitins, antibodies, hormones, erzyms, coenzyms, proteins, hydrocarbons, acids, bases, salts, water soluble and insoluble substances ! It would be very extrange that so a lot of chemical genes should not react with each other. remaining on the contrary, indefinitely the same in spite of the possibility of approaching and touching due to the stato of extreme distension of the chromosomes mouving within the fluid medium of the resting nucleus. If a given medium becomes acid in virtue of the presence of a free copy of an acid gene, then gene and character must be essentially the same thing and the difference between genotype and phenotype disappears, epigenesis gives up its place to preformation, and genetics goes back to its most remote beginnings. The author discusses the complete lack of arguments in support of the view that genes are corpuscular entities. To show the emharracing situation of the genetist who defends the idea of corpuscular genes, Dobzhansky's (1944) assertions that "Discrete entities like genes may be integrated into systems, the chromosomes, functioning as such. The existence of organs and tissues does not preclude their cellular organization" are discussed. In the opinion of the present writer, affirmations as such abrogate one of the most important characteristics of the genes, that is, their functional independence. Indeed, if the genes are independent, each one being capable of passing through mutational alterations or separating from its neighbours without changing them as Dobzhansky says, then the chromosome, genetically speaking, does not constitute a system. If on the other hand, theh chromosome be really a system it will suffer, as such, the influence of the alteration or suppression of the elements integrating it, and in this case the genes cannot be independent. We have therefore to decide : either the chromosome is. a system and th genes are not independent, or the genes are independent and the chromosome is not a syntem. What cannot surely exist is a system (the chromosome) formed by independent organs (the genes), as Dobzhansky admits. The parallel made by Dobzhansky between chromosomes and tissues seems to the author to be inadequate because we cannot compare heterogeneous things like a chromosome considered as a system made up by different organs (the genes), with a tissue formed, as we know, by the same organs (the cells) represented many times. The writer considers the chromosome as a true system and therefore gives no credit to the genes as independent elements. Genetists explain position effects in the following way : The products elaborated by the genes react with each other or with substances previously formed in the cell by the action of other gene products. Supposing that of two neighbouring genes A and B, the former reacts with a certain substance of the cellular medium (X) giving a product C which will suffer the action, of the latter (B). it follows that if the gene changes its position to a place far apart from A, the product it elaborates will spend more time for entering into contact with the substance C resulting from the action of A upon X, whose concentration is greater in the proximities of A. In this condition another gene produtc may anticipate the product of B in reacting with C, the normal course of reactions being altered from this time up. Let we see how many incongruencies and contradictions exist in such an explanation. Firstly, it has been established by genetists that the reaction due.to gene activities are specific and develop in a definite order, so that, each reaction prepares the medium for the following. Therefore, if the medium C resulting from the action of A upon x is the specific medium for the activity of B, it follows that no other gene, in consequence of its specificity, can work in this medium. It is only after the interference of B, changing the medium, that a new gene may enter into action. Since the genotype has not been modified by the change of the place of the gene, it is evident that the unique result we have to attend is a little delay without seious consequence in the beginning of the reaction of the product of B With its specific substratum C. This delay would be largely compensated by a greater amount of the substance C which the product of B should found already prepared. Moreover, the explanation did not take into account the fact that the genes work in the resting nucleus and that in this stage the chromosomes, very long and thin, form a network plunged into the nuclear sap. in which they are surely not still, changing from cell to cell and In the same cell from time to time, the distance separating any two genes of the same chromosome or of different ones. The idea that the genes may react directly with each other and not by means of their products, would lead to the concept of Goidschmidt and Piza, in accordance to which the chromosomes function as wholes. Really, if a gene B, accustomed to work between A and C (as for instance in the chromosome ABCDEF), passes to function differently only because an inversion has transferred it to the neighbourhood of F (as in AEDOBF), the gene F must equally be changed since we cannot almH that, of two reacting genes, only one is modified The genes E and A will be altered in the same way due to the change of place-of the former. Assuming that any modification in a gene causes a compensatory modification in its neighbour in order to re-establich the equilibrium of the reactions, we conclude that all the genes are modified in consequence of an inversion. The same would happen by mutations. The transformation of B into B' would changeA and C into A' and C respectively. The latter, reacting withD would transform it into D' and soon the whole chromosome would be modified. A localized change would therefore transform a primitive whole T into a new one T', as Piza pretends. The attraction point-to-point by the chromosomes is denied by the nresent writer. Arguments and facts favouring the view that chromosomes attract one another as wholes are presented. A fact which in the opinion of the author compromises sereously the idea of specific attraction gene-to-gene is found inthe behavior of the mutated gene. As we know, in homozygosis, the spme gene is represented twice in corresponding loci of the chromosomes. A mutation in one of them, sometimes so strong that it is capable of changing one sex into the opposite one or even killing the individual, has, notwithstading that, no effect on the previously existing mutual attraction of the corresponding loci. It seems reasonable to conclude that, if the genes A and A attract one another specifically, the attraction will disappear in consequence of the mutation. But, as in heterozygosis the genes continue to attract in the same way as before, it follows that the attraction is not specific and therefore does not be a gene attribute. Since homologous genes attract one another whatever their constitution, how do we understand the lack cf attraction between non homologous genes or between the genes of the same chromosome ? Cnromosome pairing is considered as being submitted to the same principles which govern gametes copulation or conjugation of Ciliata. Modern researches on the mating types of Ciliata offer a solid ground for such an intepretation. Chromosomes conjugate like Ciliata of the same variety, but of different mating types. In a cell there are n different sorts of chromosomes comparable to the varieties of Ciliata of the same species which do not mate. Of each sort there are in the cell only two chromosomes belonging to different mating types (homologous chromosomes). The chromosomes which will conjugate (belonging to the same "variety" but to different "mating types") produce a gamone-like substance that promotes their union, being without action upon the other chromosomes. In this simple way a single substance brings forth the same result that in the case of point-to-point attraction would be reached through the cooperation of as many different substances as the genes present in the chromosome. The chromosomes like the Ciliata, divide many times before they conjugate. (Gonial chromosomes) Like the Ciliata, when they reach maturity, they copulate. (Cyte chromosomes). Again, like the Ciliata which aggregate into clumps before mating, the chrorrasrmes join together in one side of the nucleus before pairing. (.Synizesis). Like the Ciliata which come out from the clumps paired two by two, the chromosomes leave the synizesis knot also in pairs. (Pachytene) The chromosomes, like the Ciliata, begin pairing at any part of their body. After some time the latter adjust their mouths, the former their kinetochores. During conjugation the Ciliata as well as the chromosomes exchange parts. Finally, the ones as the others separate to initiate a new cycle of divisions. It seems to the author that the analogies are to many to be overlooked. When two chemical compounds react with one another, both are transformed and new products appear at the and of the reaction. In the reaction in which the protoplasm takes place, a sharp difference is to be noted. The protoplasm, contrarily to what happens with the chemical substances, does not enter directly into reaction, but by means of products of its physiological activities. More than that while the compounds with Wich it reacts are changed, it preserves indefinitely its constitution. Here is one of the most important differences in the behavior of living and lifeless matter. Genes, accordingly, do not alter their constitution when they enter into reaction. Genetists contradict themselves when they affirm, on the one hand, that genes are entities which maintain indefinitely their chemical composition, and on the other hand, that mutation is a change in the chemica composition of the genes. They are thus conferring to the genes properties of the living and the lifeless substances. The protoplasm, as we know, without changing its composition, can synthesize different kinds of compounds as enzyms, hormones, and the like. A mutation, in the opinion of the writer would then be a new property acquired by the protoplasm without altering its chemical composition. With regard to the activities of the enzyms In the cells, the author writes : Due to the specificity of the enzyms we have that what determines the order in which they will enter into play is the chemical composition of the substances appearing in the protoplasm. Suppose that a nucleoproteln comes in relation to a protoplasm in which the following enzyms are present: a protease which breaks the nucleoproteln into protein and nucleic acid; a polynucleotidase which fragments the nucleic acid into nucleotids; a nucleotidase which decomposes the nucleotids into nucleoids and phosphoric acid; and, finally, a nucleosidase which attacs the nucleosids with production of sugar and purin or pyramidin bases. Now, it is evident that none of the enzyms which act on the nucleic acid and its products can enter into activity before the decomposition of the nucleoproteln by the protease present in the medium takes place. Leikewise, the nucleosidase cannot works without the nucleotidase previously decomposing the nucleotids, neither the latter can act before the entering into activity of the polynucleotidase for liberating the nucleotids. The number of enzyms which may work at a time depends upon the substances present m the protoplasm. The start and the end of enzym activities, the direction of the reactions toward the decomposition or the synthesis of chemical compounds, the duration of the reactions, all are in the dependence respectively o fthe nature of the substances, of the end products being left in, or retired from the medium, and of the amount of material present. The velocity of the reaction is conditioned by different factors as temperature, pH of the medium, and others. Genetists fall again into contradiction when they say that genes act like enzyms, controlling the reactions in the cells. They do not remember that to cintroll a reaction means to mark its beginning, to determine its direction, to regulate its velocity, and to stop it Enzyms, as we have seen, enjoy none of these properties improperly attributed to them. If, therefore, genes work like enzyms, they do not controll reactions, being, on the contrary, controlled by substances and conditions present in the protoplasm. A gene, like en enzym, cannot go into play, in the absence of the substance to which it is specific. Tne genes are considered as having two roles in the organism one preparing the characters attributed to them and other, preparing the medium for the activities of other genes. At the first glance it seems that only the former is specific. But, if we consider that each gene acts only when the appropriated medium is prepared for it, it follows that the medium is as specific to the gene as the gene to the medium. The author concludes from the analysis of the manner in which genes perform their function, that all the genes work at the same time anywhere in the organism, and that every character results from the activities of all the genes. A gene does therefore not await for a given medium because it is always in the appropriated medium. If the substratum in which it opperates changes, its activity changes correspondingly. Genes are permanently at work. It is true that they attend for an adequate medium to develop a certain actvity. But this does not mean that it is resting while the required cellular environment is being prepared. It never rests. While attending for certain conditions, it opperates in the previous enes It passes from medium to medium, from activity to activity, without stopping anywhere. Genetists are acquainted with situations in which the attended results do not appear. To solve these situations they use to make appeal to the interference of other genes (modifiers, suppressors, activators, intensifiers, dilutors, a. s. o.), nothing else doing in this manner than displacing the problem. To make genetcal systems function genetists confer to their hypothetical entities truly miraculous faculties. To affirm as they do w'th so great a simplicity, that a gene produces an anthocyanin, an enzym, a hormone, or the like, is attribute to the gene activities that onlv very complex structures like cells or glands would be capable of producing Genetists try to avoid this difficulty advancing that the gene works in collaboration with all the other genes as well as with the cytoplasm. Of course, such an affirmation merely means that what works at each time is not the gene, but the whole cell. Consequently, if it is the whole cell which is at work in every situation, it follows that the complete set of genes are permanently in activity, their activity changing in accordance with the part of the organism in which they are working. Transplantation experiments carried out between creeper and normal fowl embryos are discussed in order to show that there is ro local gene action, at least in some cases in which genetists use to recognize such an action. The author thinks that the pleiotropism concept should be applied only to the effects and not to the causes. A pleiotropic gene would be one that in a single actuation upon a more primitive structure were capable of producing by means of secondary influences a multiple effect This definition, however, does not preclude localized gene action, only displacing it. But, if genetics goes back to the egg and puts in it the starting point for all events which in course of development finish by producing the visible characters of the organism, this will signify a great progress. From the analysis of the results of the study of the phenocopies the author concludes that agents other than genes being also capaole of determining the same characters as the genes, these entities lose much of their credit as the unique makers of the organism. Insisting about some points already discussed, the author lays once more stress upon the manner in which the genes exercise their activities, emphasizing that the complete set of genes works jointly in collaboration with the other elements of the cell, and that this work changes with development in the different parts of the organism. To defend this point of view the author starts fron the premiss that a nerve cell is different from a muscle cell. Taking this for granted the author continues saying that those cells have been differentiated as systems, that is all their parts have been changed during development. The nucleus of the nerve cell is therefore different from the nucleus of the muscle cell not only in shape, but also in function. Though fundamentally formed by th same parts, these cells differ integrally from one another by the specialization. Without losing anyone of its essenial properties the protoplasm differentiates itself into distinct kinds of cells, as the living beings differentiate into species. The modified cells within the organism are comparable to the modified organisms within the species. A nervo and a muscle cell of the same organism are therefore like two species originated from a common ancestor : integrally distinct. Like the cytoplasm, the nucleus of a nerve cell differs from the one of a muscle cell in all pecularities and accordingly, nerve cell chromosomes are different from muscle cell chromosomes. We cannot understand differentiation of a part only of a cell. The differentiation must be of the whole cell as a system. When a cell in the course of development becomes a nerve cell or a muscle cell , it undoubtedly acquires nerve cell or muscle cell cytoplasm and nucleus respectively. It is not admissible that the cytoplasm has been changed r.lone, the nucleus remaining the same in both kinds of cells. It is therefore legitimate to conclude that nerve ceil ha.s nerve cell chromosomes and muscle cell, muscle cell chromosomes. Consequently, the genes, representing as they do, specific functions of the chromossomes, are different in different sorts of cells. After having discussed the development of the Amphibian egg on the light of modern researches, the author says : We have seen till now that the development of the egg is almost finished and the larva about to become a free-swimming tadepole and, notwithstanding this, the genes have not yet entered with their specific work. If the haed and tail position is determined without the concourse of the genes; if dorso-ventrality and bilaterality of the embryo are not due to specific gene actions; if the unequal division of the blastula cells, the different speed with which the cells multiply in each hemisphere, and the differential repartition of the substances present in the cytoplasm, all this do not depend on genes; if gastrulation, neurulation. division of the embryo body into morphogenetic fields, definitive determination of primordia, and histological differentiation of the organism go on without the specific cooperation of the genes, it is the case of asking to what then the genes serve ? Based on the mechanism of plant galls formation by gall insects and on the manner in which organizers and their products exercise their activities in the developing organism, the author interprets gene action in the following way : The genes alter structures which have been formed without their specific intervention. Working in one substratum whose existence does not depend o nthem, the genes would be capable of modelling in it the particularities which make it characteristic for a given individual. Thus, the tegument of an animal, as a fundamental structure of the organism, is not due to gene action, but the presence or absence of hair, scales, tubercles, spines, the colour or any other particularities of the skin, may be decided by the genes. The organizer decides whether a primordium will be eye or gill. The details of these organs, however, are left to the genetic potentiality of the tissue which received the induction. For instance, Urodele mouth organizer induces Anura presumptive epidermis to develop into mouth. But, this mouth will be farhioned in the Anura manner. Finalizing the author presents his own concept of the genes. The genes are not independent material particles charged with specific activities, but specific functions of the whole chromosome. To say that a given chromosome has n genes means that this chromonome, in different circumstances, may exercise n distinct activities. Thus, under the influence of a leg evocator the chromosome, as whole, develops its "leg" activity, while wbitm the field of influence of an eye evocator it will develop its "eye" activity. Translocations, deficiencies and inversions will transform more or less deeply a whole into another one, This new whole may continue to produce the same activities it had formerly in addition to those wich may have been induced by the grafted fragment, may lose some functions or acquire entirely new properties, that is, properties that none of them had previously The theoretical possibility of the chromosomes acquiring new genetical properties in consequence of an exchange of parts postulated by the present writer has been experimentally confirmed by Dobzhansky, who verified that, when any two Drosophila pseudoobscura II - chromosomes exchange parts, the chossover chromosomes show new "synthetic" genetical effects.

Estudos sobre o g��nero Melipona

1�� - Cita-s�� a evolu����o das abelhas segundo MIC����EN��R" (1944). 2.�� - A evolu����o dos Mel��pon��neos �� estudada sob o ponto de vista da sua biologia, estabelecendo-se o tipo do melipon��neo primitivo. 3.�� - S��o feitas considera����es sobre a distribui����o geogr��fica dos melipon��neos, entrando-se em detalhes sobre os seus fosseis, sobre a influ��ncia dos deslocamentos geol��gicos do cenozoico sobre sua distribui����o, com particular refer��ncia ao seu estabelecimento na Am��rica do Sul. Considera-se tamb��m o e$eito das glacia����es e a descontinuidade por ela provocada na distribui����o dos melipon��neos. 4.�� - S��o feitas hip��teses sobre a ��poca em que se formaram as Meliponas, sobre o processo de determina����o das castas e sua influ��ncia na evolu����o das mesmas. O tipo M. marginata �� considerado o mais primitivo dos existentes atualmente. �� dada uma hip��tese, baseada na biologia e gen��tica das Meliponas, para explicar sua evolu����o a partir de uma Tr��gona primitiva. 5.�� - Sugere-se que a M. fascisrfta (excluidas a M. punc-ticollis e M. concinnula, que necessitam de estudos) seja do tipo da Meliponatrifatorial primitiva, tomando-se por base a sua proximidade a M. marginata, sua distribui����o e sua varia����o. 6.�� - Sugere-se como centro de origem das Meliponas a Bacia Amaz��nica, por ser esse lugar a zona onde h�� maior varia����o e por ser o centro geogr��fico da ��rea habitada pelas Meliponas.

Bases para o estudo da gen��tica de popula����es dos Hymenoptera em geral e dos Apinae sociais em particular

This paper deals with problems on population genetics in Hymenoptera and particularly in social Apidae. 1) The studies on populations of Hymenoptera were made according to the two basic types of reproduction: endogamy and panmixia. The populations of social Apinae have a mixed method of reproduction with higher percentage of panmixia and a lower of endogamy. This is shown by the following a) males can enter any hive in swarming time; b) males of Meliponini are expelled from hives which does not need them, and thus, are forced to look for some other place; c) Meliponini males were seen powdering themselves with pollen, thus becoming more acceptable in any other hive. The panmixia is not complete owing to the fact that the density of the breeding population as very low, even in the more frequent species as low as about 2 females and 160 males per reproductive area. We adopted as selection values (or survival indices) the expressions according to Brieger (1948,1950) which may be summarised as follows; a population: p2AA + ��pq Aa + q2aa became after selection: x p2AA + 2pq Aa + z q��aa. For alge-braics facilities Brieger divided the three selective values by y giving thus: x/y p2 AA + y/y 2 pq Aa + z/y q��aa. He called x/y of RA and z/y of Ra, that are survival or selective index, calculated in relation to the heterozygote. In our case all index were calculated in relation to the heterozygote, including the ones for haploid males; thus we have: RA surveval index of genotype AA Ra surveval index of genotype aa R'A surveval index of genotype A R'a surveval index of genotype a 1 surveval index of genotype Aa The index R'A ande R'a were equalized to RA and Ra, respectively, for facilities in the conclusions. 2) Panmitic populations of Hymenoptera, barring mutations, migrations and selection, should follow the Hardy-Weinberg law, thus all gens will be present in the population in the inicial frequency (see Graphifc 1). 3) Heterotic genes: If mutation for heterotic gene ( 1 &gt; RA &gt; Ra) occurs, an equilibrium will be reached in a population when: P = R A + Ra - 2R��a _____________ (9) 2(R A + Ra - R��A - R��a q = R A + Ra - 2R��A _____________ (10) 2(R A + Ra - R��A - R��a A heterotic gene in an hymenopteran population may be maintained without the aid of new mutation only if the survival index of the most viable mutant (RA) does not exced the limiting value given by the formula: R A = 1 + &#8730;1+Ra _________ 4 If RA has a value higher thah the one permitted by the formula, then only the more viable gene will remain present in the population (see Graphic 10). The only direct proof for heterotic genes in Hymenoptera was given by Mackensen and Roberts, who obtained offspring from Apis mellefera L. queens fertilized by their own sons. Such inbreeding resulted in a rapid loss of vigor the colony; inbred lines intercrossed gave a high hybrid vigor. Other fats correlated with the "heterosis" problem are; a) In a colony M. quadrifasciata Lep., which suffered severely from heat, the percentage of deths omong males was greater .than among females; b) Casteel and Phillips had shown that in their samples (Apis melifera L). the males had 7 times more abnormalities tian the workers (see Quadros IV to VIII); c) just after emerging the males have great variation, but the older ones show a variation equal to that of workers; d) The tongue lenght of males of Apis mellifera L., of Bombus rubicundus Smith (Quadro X), of Melipona marginata Lep. (Quadro XI), and of Melipona quadrifasciata Lep. Quadro IX, show greater variationthan that of workers of the respective species. If such variation were only caused by subviables genes a rapid increasse of homozigoty for the most viable alleles should be expected; then, these .wild populations, supposed to be in equilibrium, could .not show such variability among males. Thus we conclude that heterotic genes have a grat importance in these cases. 4) By means of mathematical models, we came to the conclusion tht isolating genes (Ra &#094; Ra &gt; 1), even in the case of mutations with more adaptability, have only the opor-tunity of survival when the population number is very low (thus the frequency of the gene in the breeding population will be large just after its appearence). A pair of such alleles can only remain present in a population when in border regions of two races or subspecies. For more details see Graphics 5 to 8. 5) Sex-limited genes affecting only females, are of great importance toHymenoptera, being subject to the same limits and formulas as diploid panmitic populations (see formulas 12 and 13). The following examples of these genes were given: a) caste-determining genes in the genus Melipona; b) genes permiting an easy response of females to differences in feeding in almost all social Hymenoptera; c) two genes, found in wild populations, one in Trigona (Pleb��ia) mosquito F. SMITH (quadro XII) and other in Melipona marginata marginata LEP. (Quadro XIII, colonies 76 and 56) showing sex-limited effects. Sex-limited genes affecting only males do not contribute to the plasticity or genie reserve in hymenopteran populations (see formula 14). 6) The factor time (life span) in Hymenoptera has a particular importance for heterotic genes. Supposing one year to be the time unit and a pair of heterotic genes with respective survival indice equal to RA = 0, 90 and Ra = 0,70 to be present; then if the life time of a population is either one or two years, only the more viable gene will remain present (see formula 11). If the species has a life time of three years, then both alleles will be maintained. Thus we conclude that in specis with long lif-time, the heterotic genes have more importance, and should be found more easily. 7) The colonies of social Hymenoptera behave as units in competition, thus in the studies of populations one must determine the survival index, of these units which may be subdivided in indice for egg-laying, for adaptive value of the queen, for working capacity of workers, etc. 8) A study of endogamic hymenopteran populations, reproduced by sister x brother mating (fig. 2), lead us to the following conclusions: a) without selection, a population, heterozygous for one pair of alleles, will consist after some generations (theoretically after an infinite number of generation) of females AA fecundated with males A and females aa fecundated with males a (see Quadro I). b) Even in endogamic population there is the theoretical possibility of the presence of heterotic genes, at equilibrium without the aid of new mutations (see Graphics 11 and 12), but the following! conditions must be satisfied: I - surveval index of both homozygotes (RA e Ra) should be below 0,75 (see Graphic 13); II - The most viable allele must riot exced the less viable one by more than is permited by the following formula (Pimentel Gomes 1950) (see Gra-fic 14) : 4 R5A + 8 Ra R4A - 4 Ra R��A (Ra - 1) R��A - - R��a (4 R��a + 4 Ra - 1) R A + 2 R��a < o Considering these two conditions, the existance of heterotic genes in endogamic populations of Hymenoptera \&gt;ecames very improbable though not - impossible. 9) Genie mutation offects more hymenopteran than diploid populations. Thus we have for lethal genes in diploid populations: u = q2, and in Hymenoptera: u = s, being u the mutation ratio and s the frequency of the mutant in the male population. 10) Three factors, important to competition among species of Meliponini were analysed: flying capacity of workers, food gathering capacity of workers, egg-laying of the queen. In this connection we refer to the variability of the tongue lenght observed in colonies from several localites, to the method of transporting the pollen in the stomach, from some pots (Melliponi-ni storage alveolus) to others (e. g. in cases of pillage), and to the observation that the species with the most populous hives are almost always the most frequent ones also. 11) Several defensive ways used for Meliponini to avoid predation are cited, but special references are made upon the camouflage of both hive (fig. 5) and hive entrance (fig. 4) and on the mimetism (see list in page ). Also under the same heading we described the method of Lestrimelitta for pillage. 12) As mechanisms important for promoting genetic plasticity of hymenopteran species we cited: a) cytological variations and b) genie reserve. As to the former, duplications and numerical variations of chromosomes were studied. Diprion simile ATC was cited as example for polyploidy. Apis mellife-ra L. (n ��= 16) also sugests polyploid origen since: a) The genus Melipona, which belongs to a" related tribe, presents in all species so far studied n = 9 chromosomes and b) there occurs formation of dyads in the firt spermatocyte division. It is su-gested that the origin of the sex-chromosome of Apis mellifera It. may be related to the possible origin of diplo-tetraploidy in this species. With regards to the genie reserve, several possible types of mutants were discussed. They were classified according to their survival indices; the heterotic and neutral mutants must be considered as more important for the genie reserve. 13) The mean radius from a mother to a daghter colony was estimated as 100 meters. Since the Meliponini hives swarm only once a year we may take 100 meters a year as the average dispersion of female Meliponini in ocordance to data obtained from Trigona (tetragonisca) jaty F. SMITH and Melipona marginata LEP., while other species may give different values. For males the flying distance was roughly estimated to be 10 times that for females. A review of the bibliography on Meliponini swarm was made (pg. 43 to 47) and new facts added. The population desity (breeding population) corresponds in may species of Meliponini to one male and one female per 10.000 square meters. Apparently the males are more frequent than the females, because there are sometimes many thousands, of males in a swarm; but for the genie frequency the individuals which have descendants are the ones computed. In the case of Apini and Meliponini, only one queen per hive and the males represented by. the spermatozoos in its spermateca are computed. In Meliponini only one male mate with the queen, while queens of Apis mellijera L. are fecundated by an average of about 1, 5 males. (Roberts, 1944). From the date cited, one clearly sees that, on the whole, populations of wild social bees (Meliponini) are so small that the Sewall Wright effect may become of great importance. In fact applying the Wright's formula: f = ( 1/aN&#9794; + 1/aN&#9792;) (1 - 1/aN&#9794; + 1/aN&#9792;) which measures the fixation and loss of genes per generation, we see that the fixation or loss of genes is of about 7% in the more frequent species, and rarer species about 11%. The variation in size, tergite color, background color, etc, of Melipona marginata Lep. is atributed to this genetic drift. A detail, important to the survival of Meliponini species, is the Constance of their breeding population. This Constance is due to the social organization, i. e., to the care given to the reproductive individuals (the queen with its sperm pack), to the way of swarming, to the food storage intended to control variations of feeding supply, etc. 14) Some species of the Meliponini are adapted to various ecological conditions and inhabit large geographical areas (e. g. T. (Tetragonisca jaty F. SMITH), and Trigona (Nanno-trigona testaceicornis LEP.) while others are limited to narrow regions with special ecological conditions (e. g. M. fuscata me-lanoventer SCHWARZ). Other species still, within the same geographical region, profit different ecological conditions, as do M. marginata LEP. and M. quadrifasciata LEP. The geographical distribution of Melipona quadrifasciata LEP. is different according to the subspecies: a) subsp anthidio-des LEP. (represented in Fig. 7 by black squares) inhabits a region fron the North of the S. Paulo State to Northeastern Brazil, ,b) subspecies quadrifasciata LEP., (marked in Fig. 7 with black triangles) accurs from the South of S. Paulo State to the middle of the State of Rio Grande do Sul (South Brazil). In the margined region between these two areas of distribution, hi-brid colonies were found (Fig. 7, white circles); they are shown with more details in fig. 8, while the zone of hybridization is roughly indicated in fig. 9 (gray zone). The subspecies quadrifasciata LEP., has 4 complete yellow bands on the abdominal tergites while anthidioides LEP. has interrupted ones. This character is determined by one or two genes and gives different adaptative properties to the subspecies. Figs. 10 shows certains meteorological isoclines which have aproximately the same configuration as the limits of the hybrid zone, suggesting different climatic adaptabilities for both genotypes. The exis-tance of a border zone between the areas of both subspecies, where were found a high frequency of hybrids, is explained as follows: being each subspecies adapted to a special climatic zone, we may suppose a poor adaptation of either one in the border region, which is also a region of intermediate climatic conditions. Thus, the hybrids, having a combination of the parent qualities, will be best adapted to the transition zone. Thus, the hybrids will become heterotic and an equilibrium will be reached with all genotypes present in the population in the border region.

Considera����es s��bre o emprego de variedades sint��ticas no melhoramento do milho: I - sint��ticos simples

1) Inicialmente foi dado um breve resumo dos m��todos b��sicos do melhoramento no milho os quais podem ser reunidos em dois grupos principais: o processo do milho h��brido, com as suas variantes, e os processos dos sint��ticos. Estes ��ltimos podem ainda ser subdivididos em duas categorias: os sint��ticos simples e os sint��ticos balan��ados. Na obten����o dos sint��ticos simples toma-se inicialmente em considera����o a capacidade combinat��ria das linhagens a serem misturadas, e se executa em cada gera����o de sint��tico uma sele����o massal de conserva����o. Nos balan��ados devemos acrescentar uma forte sele����o, na fase preparat��ria, contra todos os h��bridos que d��o segrega����es mendelianas fortes demais. 2) No curso de um breve resumo hist��rico ficou evidente que a id��ia de se aproveitarem os sint��ticos no melhoramento do milho, formulada pela primeira vez por Hayes e Garber (1919) deu resultados pr��ticos apreci��veis. Assim Hayes, Rinke e Tsinang (1944) obtiveram produ����es de sint��ticos que eram equivalentes de um h��brido duplo, Minhybrid 403. Lonnquist (1949) registrou produ����es de sint��ticos id��nticos ao h��brido duplo, US 13. Roberts, Wellhausen, Pal��cios e Guaves (1949) e Wellhausen (1950) relataram resultados bastante satisfat��rios, obtidos no M��xico. 3) Ficou demonstrado que as f��rmulas de Sewall Wright (1932) e de Mangelsdorf (1939) n��o podem ser consideradas como explica����es gerais do m��todo, pois pela sua deriva����o pode-se mostrar facilmente que elas exigem certas premissas que nem sempre s��o justific��veis. 4) Para eliminar confus��es na terminologia foi desenvolvido um esquema b��sico da constitui����o de sint��ticos supondo que se parte de linhagens autofecundadas e que foram plantadas em conjunto para a reprodu����o de cruzamento livre. A gera����o que consiste das plantas autofecundadas, plantadas em mistura, �� denominada SyO. A gera����o seguinte, a qual cont��m uma maior percentagem de h��bridos simples e uma menor per-centagem de descendentes de cruzamentos dentro de mesma linhagem (descendentes consangu��neos) representa assim a gera����o Syl. A gera����o que segue depois de novo cruzamento livre, Sy2, ser�� ent��o composta de h��bridos entre quatro linhagens (h��bridos duplos"), entre tr��s linhagens ("three way crosses"), entre duas linhagens ("h��bridos simples") e descendentes de combina����es consangu��neas, ("inbreds"). Por��m se houver uma sele����o em Sy1 que elimina todos os descendentes de combina����es consangu��neas, sobrevivendo apenas h��bridos simples, ent��o a gera����o Sy2 ser�� composta de h��bridos entre plantas que n��o tem nenhuma das linhagens originais em comum, os que t��m uma linhagem em comum e finalmente aqueles que t��m duas linhagens em comum. 5) Empregando esta classifica����o das gera����es, podemos verificar que a gera����o Sy1 de Lonnquist corresponde �� gera����o Sy1 do esquema b��sico, a gera����o Sy1 deHayes et al corresponde �� gera����o Sy2 do esquema b��sico �� a gera����o Sy1 de Wellhausen et al corresponde aproximadamente �� gera����o Sy3 do esquema b��sico. 6) Uma teoria mais correta dos sint��ticos deve-se basear nas regras da gen��tica em popula����es, as quais foram empregadas por Brieger para justificar o processo dos sint��ticos balan��ados. Uma discuss��o mais detalhada desta teoria ser�� assim dada numa outra publica����o que se ocupara especialmente com ossint��ticos balan��ados.

Observa����es s��bre alguns dipl��podos de inter��sse agr��cola

This paper deals with some Millipedes (Diplopoda), which have been verified associated with or attacking on cultivated plants. The following forms are reported: 1) Orthomorpha (Orthomorpha) coarctata (Saussure, 1860) - Enormous numbers of individuals belonging to this species, whose synanthropic habits are frequentely emphasized, were collected around coffee-plants kept in a nursery. Young plants (with 10 cm) are mentioned as damaged by the species, which gnaws the stem, just above the roots. The dusting with benzene hexachloride (BHC) was successfully employed to prevent the invasions. Other occurrences of O. coarctata are reported, ecological and biological informations being also added. 2) Orthomorpha (Kalorthomorpha) gracilis (C. L. Koch, 1847) - Observed frequentely associated with the former species, being however less numerous. Both forms are very active, seemming to be widely distributed throughout the State of S. Paulo. 3) Cylindroiulus (Aneuloboiulus) britannicus (Verhoeff, 1891) - This species represents the first european Millipede verified in Brazil, by O. SCHUBART (1942a). The Author obtained a few specimens associated with O. gracilis, from the roots of lettuce plants. The lesions shown by the stem just above the roots seem to be due to both species. 4) Alloporus setiger Broelemann, 1902; Gymnostreptus olivaceus Schubart, 1944 and Pseudonannolene tricolor Broelemann, 1902 - Total damages determined by these species (mainly G. olivaceus) were observed in cultures of sugar-beet and melon. Actually, the Millipedes destroyed entirely the roots of the former plant and the fruits of the latter, representing a serious pest, here reported by the first time. Ecological and bionomical data are also included. 5) Pseudonannolene sp. (possibly P. paulista Broelemann, 1902) - Verified gnawing sweet-potatoes, about the crackings exhibited by the tubers. The crackings in sweet-potatoes appear to result in certain instances from a root-knot nematodes infection (Meloidogyne sp). P. paulista was recentely observed attacking potatoes, destroying from 6 to 30% of the tubers, according to the variety (BOOCK &amp; LORDELLO, 1952).

Nova contribui����o para o conhecimento das sa��vas do Estado de S��o Paulo

��ste trabalho tem como objetivo principal descrever aspectos ecol��gicos e bion��micos das sa��vas de 104 munic��pios do oeste do Estado de S��o Paulo. Em t��da a regi��o pesquisada somente tr��s esp��cies de sa��vas foram constatadas: l.��) Atta sexdens rubropilosa Forel, 1908 (sa��va lim��o); 2.��) A. laevigata (F. Smith, 1858) (sa��va-de-vidro ou sa��va cabe��a-de-vidro); 3.��) A. capiguara Gon��alves, 1944 (sa��va parda). Uma das grandes surpresas, durante o desenvolvimento d��ste trabalho, foi o de se comprovar que a sa��va parda A. capiguara �� a esp��cie mais frequente e a mais importante. A sua import��ncia e a das duas outras esp��cies ��, entretanto, salientada no cap��tulo 5 (BIONOMIA).

Ultramorphology of the metapleural gland in three species of Atta (Hymenoptera, Formicidae)

Differences among the metapleural glands of four female castes of Atta bisphaerica Forel, 1908, A. capiguara Gon��alves, 1944 and A. sexdens rubropilosa Forel, 1908 were examined by scanning electron microscope. There were no differences in gland size between the same castes of these species, although the opening gland in A. sexdens rubropilosa had been twice as large as A. bisphaerica. The relative size and functional significance of the metapleural gland among different castes is discussed and similarities between these and the other Formicidae till now studied is presented.

Revis��o taxon��mica do g��nero Homodiaetus (Teleostei, Siluriformes, Trichomycteridae)

The genus Homodiaetus Eigenmann &amp; Ward, 1907 is revised and four species are recognized. Its distribution is restricted to southeastern South America, from Uruguay to Paraguay river at west to the coastal drainages of Rio de Janeiro State, Brazil. Homodiaetus is currently distinguished from other genus of Stegophilinae by the combination of the following characters: origin of ventral-fin at midlength between the snout tip and the caudal-fin origin; opercle with three or more odontodes; and gill membranes confluent with the istmus. Homodiaetus anisitsi Eigenmann &amp; Ward, 1907, is diagnosed by the caudal-fin with black middle rays, margin of upper and lower procurrent caudal-fin rays with dark stripes extending to the caudal-fin, and 3-6 opercular odontodes; H. passarellii (Ribeiro, 1944) with 6-7 opercular odontodes, 21-24 lower procurrent caudal-fin rays and 23-26 upper procurrent caudal-fin rays; H. banguela sp. nov. with 9 opercular odontodes, 17-19 lower procurrent caudal-fin rays, 17-22 upper procurrent caudal-fin rays, reduction of fourth pharyngobranchial with only three teeth and untoothed fifth ceratobranchial; and H. graciosa sp. nov. with 5-6 dentary rows, 7-9 opercular odontodes and 16-23 upper procurrent caudal-fin rays.

Cerambycidae (Coleoptera) da Col��mbia: I. Eburiini (Cerambycinae)

New records added to the Colombian fauna: Susuacanga unicolor (Bates, 1870), Opades costipennis (Buquet, 1844), Eburodacrys havanensis Chevrolat, 1862, E. granipennis Gounelle, 1909, E. moruna Martins, 1997, E. nemorivaga Gounelle, 1909, E. pilicornis Fisher, 1944. New species described: Pantomallus martinezi, from Cundinamarca and Meta and Beraba inermis, from Cundinamarca.

O g��nero Eustala (Araneae, Araneidae) no sul do Brasil: duas esp��cies novas, descri����es complementares e novas ocorr��ncias

Eustala levii sp. nov. e E. palmares sp. nov. s��o descritas do Rio Grande do Sul, Brasil, com base em ambos os sexos. Os machos de E. albiventer (Keyserling, 1884), E. taquara (Keyserling, 1892) e E. photographica Mello-Leit��o, 1944, s��o descritos pela primeira vez e as f��meas s��o redescritas. Eustala sanguinosa (Keyserling, 1893) �� considerada sin��nimo de E. albiventer. Eustala photographica, descrita da Argentina, �� registrada pela primeira vez para o Brasil. Novas ocorr��ncias ampliam a distribui����o geogr��fica de E. minuscula (Keyserling, 1892) e E. saga (Keyserling, 1893).

Tr��s esp��cies novas de Cryptachaea e notas taxon��micas em Theridiidae (Araneae)

Tr��s esp��cies novas de Cryptachaea Archer, 1946 s��o descritas e ilustradas, com base em ambos os sexos: Cryptachaea brescoviti sp. nov. de Beni, Bol��via e Bahia e Esp��rito Santo, Brasil; C. bonaldoi sp. nov. de Minas Gerais, Mato Grosso do Sul e Paran�� e C. lisei sp. nov. de S��o Paulo e Rio Grande do Sul, Brasil. Sinon��mias novas s��o propostas: Chrysso ribeirao Levi, 1962 e C. caraca Levi, 1962 com Chrysso arops Levi, 1962; Cryptachaea diamantina (Levi, 1963) com C. hirta (Taczanowski, 1873) e Cryptachaea maxima (Keyserling, 1884) com C. altiventer (Keyserling, 1884). Theridion altum Levi, 1963 �� sin��nimo j��nior de Theridion soaresi Levi, 1963. Theridion melanosternum Mello-Leit��o, 1947 �� sinonimizada com Oedothorax bisignatus Mello-Leit��o, 1944 e esta ��ltima esp��cie �� removida da sinon��mia de Theridion calcynatum Holmberg, 1876 e transferida para Theridion Walckenaer, 1805. Theridion tungurahua Levi, 1963 �� a f��mea de Theridion fungosum Keyserling, 1884 e a esp��cie �� transferida para Exalbidion Wunderlich, 1995. Theridion antron Levi, 1963 �� a f��mea de Theridion filum Levi, 1963. Theridion nesticum Levi, 1963 �� sinonimizada com Theridion teresae Levi, 1963. Theridion olaup Levi, 1963 �� transferida para Kockiura Archer, 1950 e a f��mea �� descrita e ilustrada pela primeira vez. Novas combina����es s��o estabelecidas: Cryptachaea dalana (Buckup &amp; Marques, 1991), C. triguttata (Keyserling, 1891), C. dea (Buckup &amp; Marques, 2006), C. digitus (Buckup &amp; Marques, 2006), C. taim (Buckup &amp; Marques, 2006) e Parasteatoda nigrovittata (Keyserling, 1884), todas s��o transferidas de Achaearanea Strand, 1929. Cryptachaea rafaeli (Buckup &amp; Marques, 1991) �� transferida para Henziectypus Archer, 1946.

Estrutura da comunidade de Phlebotominae (Diptera, Psychodidae) em mata ciliar do munic��pio de Urbano Santos, Maranh��o, Brasil

A diversidade, abund��ncia relativa e a distribui����o de Phlebotominae foram estudadas em tr��s setores (bordas e centro) de um fragmento de mata ciliar no munic��pio de Urbano Santos, Maranh��o, Brasil. Os esp��cimes foram capturados em junho e novembro/2003 e em janeiro e mar��o/2004 das 18 ��s 6 horas. Em cada noite de coleta foram instaladas 18 armadilhas, seis em cada setor da mata, totalizando um esfor��o de 864 horas. Foram encontradas 17 esp��cies. O centro do fragmento obteve a maior riqueza de esp��cies (14), seguido da borda B (13) e da borda A (12). As esp��cies Lutzomyia infraspinosa (Mangabeira, 1941), L. flaviscutellata (Mangabeira, 1942) e L. evandroi (Costa Lima &amp; Antunes, 1936) foram as ��nicas que apareceram como dominantes nos tr��s setores da mata. Quatorze esp��cies ocorreram em ambas esta����es, sendo que L. fluviatilis (Floch &amp; Abonnenc, 1944) foi encontrada apenas na esta����o chuvosa (janeiro e mar��o) e L. migonei (Fran��a, 1920) e L. pinottii (Damasceno &amp; Arouck, 1956) apenas na esta����o seca (junho e novembro). As diferen��as registradas na abund��ncia de indiv��duos entre as esta����es n��o foram estatisticamente significativas. A presen��a frequente de L. flaviscutellata pode explicar um caso de leishmaniose cut��nea difusa em uma paciente deste munic��pio.

Descripci��n de tres especies nuevas del g��nero Drosophila (Diptera, Drosophilidae) en el Ecuador

Se encontraron tres especies nuevas de Drosophila entre los individuos colectados en diferentes localidades del Ecuador. Una de las especies nuevas pertenecen al grupo Drosophila willistoni y otra al grupo Drosophila asiri, la tercera especie se encuentra sin agrupar. En todos los muestreos realizados se usaron trampas fabricadas con botellas de pl��stico agujereadas con cebo de banano y levadura. Las tres especies son: D. (Sophophora) neocapnoptera sp. nov., esta especie es similar a D. capnoptera Patterson &amp; Mainland, 1944, sin embargo presentan algunas diferencias en el ala que permiten distinguirlas. Drosophila (Drosophila) neoasiri sp. nov., una especie similar a D. asiri Vela &amp; Rafael, 2005, la diferencia m��s relevante entre las dos especies se observa a nivel del edeago y Drosophila (Drosophila) papallacta sp. nov. que por el momento no se encuentra relacionada a ning��n grupo de especies del g��nero Drosophila.