II - Contribuição para o estudo biológico e ecológico das podostemonaceae do salto de Piracicaba

Resumindo as observações feitas sobre a biologia e a ecologia das espécies Apinagia Accorsii Toledo e Mniopsis Glazioviana Warmg., Podostemonaceae que vivem incrustadas às rochas diabásicas do Salto de Piracicaba, durante os anos de 1943, 1944 e 1945, cheguei às conclusões seguintes: a) Com o início do período de enchente do Salto de Piracicaba, variável de ano para ano, mas que, no geral, começa com as primeiras chuvas de outubro e se prolonga até fins de março, processa-se o desenvolvimento vegetativo das Podostemonaceae, com a formação de estolhos (Fig. 15-B) dotados de gemas produtoras de novos rizomas (Fig. 16-A, C, D, E) e regeneração dos rizomas primitivos (Fig. 15-B), quando em determinadas condições, em Apinagia Accorsii; raízes hemicilindricas com produções faliáceas, dispostas aos pares. (Fig. 19-A,B, C,D,E,F,G,H), provenientes de gemas, em Mniops's Glazioviana, Demais, em ambas as espécies realiza-se ainda a germinação das sementes nos seguintes substratos : placentas, cápsulas e pedicelos de frutos (Figs. 16, 17, 18 e 20), resíduos orgânicos de várias procedências, inclusive os provenientes das próprias Podostemonaceae, que se acumulam em quantidade apreciável entre as plantas e sobre as rochas, etc. A Ap-nagia Accorsii, além desses meios, conta ainda com os resíduos rizomáticos, com os caules e mesmo com a superficies dos rizomas (Fig. 21-H). A massa rizomática constitui excelente meio para a retenção germinação das sementes. b) A deiscência dos frutos dá-se ao contacto do ar seco. As sementes podem fixar-se aos substratos citados, devido à transformação do tegumento externo em mucilagem. c) Dentre os substratos para a germinação das sementes, o mais importante e mesmo decisivo, em determinadas circunstâncias, para a garantia da espécie no habitat, é o fruto. Após a deiscência, algumas sementes podem colar-se às paredes internas da cápsula e aos pedicelos, graças à mucilagem do tegumento externo, ao passo que outras permanecem sôbre a placenta. d) Os "seedlings" não apresentam raiz principal. Todavia, à volta de toda a extremidade do hipocótilo, produz-se enorme quantidade de pêlos radiculares, cuja principal função é servir de órgãos de fixação. A incrustação das plantas ao substrato é feita por meio de pêlos radiculares, ou, mais freqüentemente, por "haptera". Segundo WILLIS (1915), "os "haptera" são órgãos adesivos especiais, provavelmente de natureza radicular, que aparecem como protuberância exógenas da raiz ou do caule e se curvam para a rocha, onde se fixam e se achatam, segregando uma substância viscosa". e) Os "seedlings", que se desenvolvem sobre as cápsulas, pedicelos, etc., encontrando condições ecológicas favoráveis, transformam-se rapidamente em plantas jovens; os novos rizomas já começam a produzir caules e em tudo se assemelham aos rizomas provenientes dos estolhos. É o que se observa no habitat, por ocasião da germinação das sementes. f) As transferência das plantinhas, que so desenvolvem nos substratos citados para a superfície da rocha, realiza-se quando elas alcançarem o peso suficiente para curvar o pedicelo do fruto. (Figs. 17 e 18), promovendo, assim, o contacto da cápsula com a rocha. Daí por diante, o novo rizoma vai aderindo ao substrato natural, através da produção dos órgãos especiais de fixação, isto é, pêlos radiculares e "haptera". O mecanismo da Devido a um pequeno engano na feitura dos clichés, os aumentos das figuras 15, 16, 19 e 20, constantes da legenda, passarão a ser respectivamente :- 1,9 - 1,65 - 2,3 e 2,9. 39 transferência das plantas jovens que, inicialmente, se desenvolvem sobre cápsulas, pedicelos, etc., para o substrato definitivo - a rocha - foi verificado, freqüentes vezes, em farto material que incluia vários estágios de desenvolvimento vegetativo (Figs. 16, 17, 18, 20). g) As cápsulas, compreendendo, além da placenta (em certos casos), as paredes internas e externas, e os pedicelos dos frutos de ambas as espécies estudadas constituem excelentes e importantes meios para a fixação das sementes. Após os longos periodos de seca, quando toda a parte vegetativa se destroi, tornam-se os únicos substratos apropriados para o fenômeno da germinação. h) Iniciada a fase vegetativa e, à medida que progride a submersão das plantas, acentuam-se, cada vez mais, o crescimento e o desenvolvimento. É precisamente durante a época de submersão que as Podostemonaceae encontram o ambiente mais adequado ao seus desenvolvimento vegetativo, alcançando, ao mesmo tempo, a máxima distribuição local, mormente a espécie Apinagia Accorsii Toledo, que chega a cobrir todas as rochas situadas da região frontal da cachoeira. i) O declínio das águas começa, aproximadamente, em fins de março, com as últimas chuvas. Pode-se, então, avaliar a extensão do desenvolvimento vegetativo que as plantas alcançaram, durante a fase de enchente. O nível da correnteza vai, daí por diante, baixando gradativamente, até fins de setembro, quando atinge o mínimo, ocasião em que o Salto se apresenta com o máximo de rochas expostas. j) Durante todo o período de vazante, que é variável e dependente do regime de chuvas que vigorar, as plantas vão paulatinamente emergindo, ao mesmo tempo que cessa o desenvol-vimnto vegetativo, para entrar em atividade o ciclo floral. Antes, porém, os caules de Apinagia que estiveram submetidos às fortes vibrõações da correnteza se destacam (Fig. 21-A,C,F,G, H,I). Todavia, as plantas, que se desenvolveram em regiões de correnteza mais branda, não chegam a perder os seus caules. k) As gemas floríferas, à medida que vão emergindo, desabrochan!. As flores desenvolvem-se rapidamente; a polinização que é direta efetua-se em plena atmosfera, quando as anteras enxutas e suficientemente dessecadas sofrem a deiscência, libertando o pólen. Realizada a fecundação, as sementes atingem depressa a maturidade. Como todo o desenvolvimento compreendido entre o desabrochar das gemas e a frutificação se processa fora da água e como a exposição das plantas é gradativa, em virtude do lento declínio das águas, compreende-se que no Salto existam, a um tempo, todos os estágios do ciclo vegetativo ao lado de todas as fases do desenvolvimento floral. l) Os rizomas, em contacto com o ar e sob a ação solar, dessecam-se, transformando-se em placas duras, fortemente inscrustadas às rochas. Mas, se durante a dessecação forem umidecidos, de quando em quando, passam a constituir excelente meio para a retenção e germinação das sementes. m) No período seguinte de enchente e vazante, repetem-se, para as espécies estudadas, todas as fases do desenvolvimento vegetativo e floral, assinaladas nesta contribuição.

Aspectos interessantes observados na meiose de alguns hemípteros

Particular aspects of the meiosis of two species of Hemiptera, namely Megalotomus pallescens (Stal) (Coriscidae) and Jadera sanguinolenta (Fabr.); (Corizidae) are described and discussed in this paper. Megalotomus pallescens This species has primary spermatocytes provided with 7 autosomal tetrads plus a single sex chromosome. The X is smaller than the autosomes and may be found either in the periphery of the circle formed by the autosomal tetrads or in the center together with the m-tetrad which always occupies this position. The X chromosome - In the primary spermatocytes this element, which is tetradiform, orients itself parallelly to the spindle axis and divides transversely by its median constriction. In the secondary spermatocytes it passes undivided to one pole. The m-chromosomes - These chromosomes have been frequently found in close association with the sex chromosome in nuclei wich have passed the diffuse stage, a fact which was considered as affording some evidence in support of the idea /developed by the present writer in another paper with regard to the origin of the m-chromosomes from the sex chromosome. Formation of tetrads - Tetrads appear at first as irregular areas of reticular structure, becoming later more and more distinct. Then, two chromosomal strands very loose and irregular in outline, connected whit each other by several transverse filaments, begin to develop in each area. Growing progressively shorter, thicker and denser, these strands soon give origin to typical Hemiptera tetrads. Jadera sanguinolenta Spermatogonia of this species have 13 chromosomes, that is, 10 autosomes, 2 m-chromosomes and one sex chromosome, one pair of autosomes being much larger than the rest. Chromosomes move toward the poles with both ends looking to them. Primary spermatocytes show 6 tetrads and a single X. The sex chromossome in the first division of the spermatocytes divides as if it was a tetrad, passing undivided to one pole in the second division. In the latter it does not orient, being found anywhere in the cells. Its most common situation in anaphase corresponds therefore to precession. Tetrads are formed here in an entirely different way : the bivalents as they become distinct in the nuclei which came out. of the diffuse stage they appear in form of two thin threads united only at the extremities, an aspect which may better be analized in the larger bivalent. Up from this stage the formation of the tetrads is a mere process of shortening and thickening of both members of the pair. Due to the fact that the paired chromosomes are well separated from each other throughout their entire lenght, the author concluded that chiasmata, if present, are accumulated at the very ends of the bivalents. If no chiasmata have been at all formed, then, what holds together the corresponding extremities must be a strong attraction developed by the kinetochores. If one interprets the bivalents represented in the figures 17-21 as formed by four chromatids paired by one of the ends and united by the opposite one, then the question of the diffuse attachment becomes entirely disproved since it is exactly by the distal extremities that the tetrads later will be connected with the poles. In the opinion of the present writer the facts referred to above are one of the best demonstration at hand of the continuity of the paired threads and at the same time of the dicentricity of Hemiptera chromosomes. In view of the data hitherto collected by the author the behavior of the sex chromosome of the Hemiptera whose males are of the XO type may be summarized as follows: a) The sex chromosome in the primary metaphase appears longitudinally divided, without transverse constriction. It is oriented with the extremities in the plane of the equator and its chromatids separate by the plane of division. (Euryophthalmus, Protenor). In the second division the sex chromosome, provided as it is with an active kinetochore at each end, orients itself with its lenght parallelly to the spindle axis and passes undivided to one pole (Protenor?), or loses to the other pole a centric end (Euryophthalmus) In the latter case it has to become dicentric by means of a longitudinal spliting beginning at the kinetochore. b) The sex chromosome in the primary metaphase is tetradiform, that is, it is provided with a longitudinal split and a median transverse constriction. Orients with its length paral lelly to the spindle axis (what is probably due to the kinetochores being not yet divided) and divides transversely. (Corizas hyalinus, Megalotomus pallescens). in the secondary metaphase the sex chromosome which turned to be dicentric in consequence of a longitudinal spliting initiated in the kineto chore, orients perpendicularly to the equatorial plane and without losing anyone of its extremities passes undivided to one pole (Megalotomus). Or, distending between both poles passes to one side, in which case it loses one of its ends to the other side. (Corizas hyalinus). c) The very short sex chromosome in the first division of the spermatocytes orients in the same manner aa the tetrads and divides transversely. In the second division, due to the inactivity o the inetochore, it remains monocentric and motionless anywhere in the cell, finishing by being enclosed in the nearer nucleus. In the secondary telophase it recuperates its dicentricity at the same time as the autosomal chromatids. (Jadera sanguinolenta, Diactor bilineatus). d) The sex chromosome in the first division orients in the equador with its longitudinal axis parallelly to the spindle axis passing integrally to one pole or, distending itself between the anaphase plates, loses one of its ends to the opposite pole. In this case it becomes dicentric in the prometaphase of the second division, behaving in this division as the autossomes. It thus divides longitudnally. (Pachylis laticomis, Pachylis pharaonis).

Influência do carvão na alimentação das aves

Dois lotes de 50 pintos foram submetidos, durante 25 dias, ao mesmo regime, salvo que um (A) recebeu 5% de carvão na farelada e outro (B) não. No fim da experiência, a média de peso do lote A era 174,9 grs. e a do lote B, 262,2; a diferença é significativamente favorável ao lote B em relação ao peso, contudo a mortalidade foi maior (12%) no lote que não recebeu carvão. A aparência geral dos pintos do lote B era muito melhor. Os AA. concluem que o carvão não deve ser usado como alimento, provavelmente por absorver muitas subtâncias úteis à nutrição, possivelmente vitaminas e amino-ácidos, mas sim para os pintos que se atrazam no crescimento devido a perturbações do aparelho digestivo, como um medicamento. Esta última conclusão depende de ulterior comprovação, pois a maior mortalidade constatada no lote sem carvão pode ser devida ao acaso, simplesmente.

Comparação de Proteínas: alimentação das aves I

Beginning an experiment on protein comparisons, at the Poultry and Rabbitry Departament of the Esc. Sup. de Agricultura "Luiz de Queiroz", University of S. Paulo, four groups of growing chicks were submitted during 40 days to the following rations: basal part - 50 corn meal and 30 wheat bran, variable part - R1 - 10 tankage and 10 peanut meal, R2 - 10 tankage and 10 cottonseed meal, R3 - 7 peanut meal, 7 cocoanut meal and 7 cottonseed meal, R4 - 5 tankage, 5 peanut, 5 cocoanut and 5 cottenseed meal, R2 and R3 gave results which may be considered as equal and inferior than those obtained with the others, R4 being the best one. The statistical analises showed no significant differences.

A couve flor na alimentação da galinha: influência sôbre a postura

Os autores realizaram uma pesquisa afim de verificar o conceito de que a couve-flor exerce um papel deprimente sobre a postura das galinhas. Para isso organizaram 20 grupos de 10 aves cada, onze dos quais da raça Rhode Island Red e 9 da Light Sussex. Desses grupos, 7 ocupavam parques gramados e os restantes parques sem grama. As aves permaneceram por 10 dias sob o regime verde de couve-flor. Houve dificuldade na análise dos resultados devido a diferenças genéticas entre as duas raças utilizadas. Das conclusões parciais constantes do texto deste trabalho, parece que a couve-flor exerce um efeito deprimente sôbre a postura, mas essa crença não chega a ser confirmada clarament na análise estatística dos dados obtidos. A conclusão final a que os AA. chegaram é que, se existe um efeito nocivo do suprimento de couve-flor, nas aves em postura, êsse efeito não chegaria a ser economicamente prejudicial, em vista do fato da couve-flor, sob a forma de folhas externas, refugo. só ser fornecida às aves, esporadicamente, durante períodos relativamente curtos, que correspondem aos da colheita das "cabeças" para serem entregues ao mercado, e, como demonstra a experiência, o suprimento por poucos dias não chega a prejudicar notavelmente a postura.

A influência dos pigmentos amarelo-laranja da semente de milho na coloração da gema de ovo de galinha

The effect of carotenoid pigments on the egg yolk color was studied in this paper. Three types of maize of known genetical constitution were used: Cateto, with deep orange endosperm; Armour, with yellow-orange endosperm and Cristal, with white endosperm. The carotenoid pigments of the two colored maizes were analysed: the total and both the active parts in relation to vitamin A and the zeaxanthin part showed to be practically double in the deep orange corn. The color of the yolk was orange when the ration had the deep orange corn and yellow in the case of the yellow-orange corn. The increase in shade was proportional to the amount of pigment present in the grains. If green feeds is added to the ration with white corn, the yolk becomes yellow or orange, depending on the amount of green given to the chickens. The practical importance of controlling the color of the yolk was emphasized.

A ração úmida no crescimento dos pintos

The author reports in this paper the results obtained in one experiment with wet an dry mash on the growing of chickens. The experiment started with two groups of 50 Sussex bred each, one receiving dry and other wet mash. The observations were continued in another four groups of 25 chickens each, two of Rhod Island Red bred and two of Sussex bred, both receiving dry and wet mash. The chickens were weight every 10 days and the differences obtained proved to be not significant statistically. Both dry and wet mash were equally good but wet mash is much more dificult to give to the chickkens than the dry one.

Envelhecimento das aguardentes

1 - Colour, by itself, does not constitute a solid ground for judging of the age of a brandy because the more or less pronounced colour it acquires through aging can also be obtained by the addition of oack essence to newly distilled brandy. 2 - Urder the same conditions, colour intensity of a brandy wiU depend upon the nature of the wood and the condition of the storage. 3 - In accordance with the experimental results obtained by the present writers it rests no doubt that fermentation facility ferment resistence, produce and quality of the brendy all are factors depending upon the variety of the sugar cane. In addition, the authors presume that the variety of sugar cane has also influence upon the alteration of composition of the brandy submitted to aging. 4 - All aging phenomena of the brandy are accompanied by volume decreasing, what happens in a slow and continuous manner depending upon storage and environment conditions 5 - During brandy aging the alcoholic degree is greatly af- fected by evaporation, increasing or decreasing in accordance to the hygrometric state of the air and the teriperature in the place where the tuns are stored. 6 - The specific weight of the brandy is inversely proportio- nal to its alcoholic degree, but directly proportional to the extracts since the latter indicates the amount of dissolved residues. 7 - Brandy which shows high specific weight together with high alcoholic degree cannot be considered as aged. It may, however, be takens for brandy artificially coloved in order to conceal its actual age. 8 - The amount of extracts increases with aging, since it is the result of the solvent action of the brandy upon the soluble extractive substances of the wood. Notwithstanding that the extract, considered alone, has no value in determining the age of a brandy, since nothing easier is ohan to nake it change artificially. 9 -During aging the brandy get acidity in physiological as well as in physical way, but never by the action of microorganisms. 10 - The estturs produced during aging by the action of acids upon alcohols are the mean factors of the savour (bouquet) of a brandy and therefore every thing shall be done tor fhr estherification of a preserved brandy being not limited. 11 - Aeration increases esther formation, reduces the aging- time and turn better the taste qualities of the brandy. 12 - Due to the great proportion of high alcohols ordinarily found in the brandy, their analytical discrimination will be greatly important. 13 - The high alcohols are not responsable for the disastrous consequences of the alcoholism, but the high percentage of uthyl alcohol present in the brandy. 14 - The aldehydes appear always in high rate in the brazilian brandys in consequence of some intermediary products of the oxydation of the alcohols being left in the brandys during aging. 15 - The age has little or no influence on the quantity of phurphurol present in a brandy whose amount varies greatly the manner in which the wines to be distilled are treated. Wines centrifugalized or filtered before distillation always give rise to brandys poorer in phurphurol as compared with those distilled without these treatments. 16 - Though greatly variable, brandys of good qualities generally show a high residues coefficient, never under 200 mmg 17 - Lusson - Rocques oxydation coefficient cannot be indis- criminately applied to any brandy class, being, on the contrary, specifically destined to cognacs.

Raça de galinhas "piracicaba" I: hereditariedade dos caracteres pescoço pelado e plumagem preta

The characters naked neck and black plumage proved to be due to single genes in a group of chicks growing at the Poultry Department of "Luiz de Queiroz" School of Agriculture, Piracicaba, Brasil. The two characters segregate independently and the animals with known genetical constitution will be used in the formation of a local breed.

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.