A new genus and species of gall midge (Diptera, Cecidomyiidae) associated with Microgramma vacciniifolia (Langsd. & Fisch.) Copel. (Polypodiaceae) from Brazil

A new genus and species of gall midge (Diptera, Cecidomyiidae) associated with Microgramma vacciniifolia (Langsd. & Fisch.) Copel. (Polypodiaceae) from Brazil. A new gall midge genus Primadiplosis Maia, gen. nov. and a new species, P. microgrammae Maia,sp. nov., that induces galls on stems of the fern Microgramma vacciniifolia (Langsd. & Fisch.) Copel. are described from Brazil (larva, pupa, male, female, and gall).

Richness of gall-inducing insects in the tropical dry forest (caatinga) of Pernambuco

Diversity of gall-inducing insects in the tropical dry forest (caatinga) of Pernambuco. We report on the richness of galling insects in the vegetation of caatinga of Pernambuco state, Brazil. We recorded 64 different types of galls collected primarily from leaves and stems of 48 species of host plants belonging to 17 families and 31 genera. The most common gall morphological types were spheroid and discoid, glabrous, predominantly green and with one chamber. The main gall inducing taxon was the Cecidomyiidae (Diptera). The results of this study contribute to existing knowledge of galling insect and host-plant diversity in caatinga.

Spatial distribution of a spherical gall (Hymenoptera, Eulophidae) on Caryocar brasiliense (Caryocaraceae)

We obtained the first data on spatial distribution of a spherical galling insect (Hymenoptera, Eulophidae) at the Caryocar brasiliense Camb. (Caryocaraceae) tree level. This work was developed in two pastures in Montes Claros, Minas Gerais State, Brazil. The areas studied were: pasture 1 (in activity) and pasture 2 (abandoned pasture = savanna in recovery). We evaluated the distribution of spherical galls in: foliage orientation (slope), among leaves (border and interior of the tree crown), among leaflets (right, central, left), distal, median, and proximal as well as border, central area, and adjacent to the mid leaf vein of the leaflet, and difference between areas in 10 infested trees per area. The smaller number of spherical gall/leaflet was observed in pasture 1 than in pasture 2. More spherical galls were found on the northern in pasture 1, but in the pasture 2, the lower spherical galls were observed on the northeast than other slopes. The average number of spherical galls did not differ statistically among the three leaflets of C. brasiliense in pasture 2. However, in pasture 1, we observed highest number of spherical galls in the central leaflet. More spherical galls were found in the border than interior of the tree crown. The average number of spherical galls did not differ statistically among the longitudinal region on leaflet of C. brasiliense. The spherical gall insect preferred to colonize the leaf margin than the central portion or near mid vein on transversal regions on a leaflet.

Gall-inducing insects of an Araucaria Forest in southern Brazil

Gall-inducing insects of an Araucaria Forest in southern Brazil. Diversity of galling insects is reported for the first time in an Araucaria Forest site. We address gall characteristics, host plant identification and the inducer identification and provide additional information about sites of gall occurrence in a mosaic of continuous forest and natural forest patches. After 40h of sampling we found 57 species of five insect orders, the majority of them Diptera (Cecidomyiidae), galling 43 host plant species, which in turn belonged to 18 host plant families. Stem and buds together, compared to leaves, harbored more galls, which were mostly glabrous, isolated, fusiform and green. Myrtaceae, Asteraceae and Melastomataceae were the most representative host families. Similarities in gall characteristics to what has been reported in the literature probably result from spatial correlation in a larger scale driven by ecological and evolutionary processes.

Description of the immature stages of the weevil Anthonomus vis Clark (Coleoptera, Curculionidae), inquiline into the gall of Leandra aurea (Melastomataceae)

Description of the immature stages of the weevil Anthonomus vis Clark (Coleoptera, Curculionidae), inquiline into the gall of Leandra aurea (Melastomataceae). The third instar larva and the pupa of Anthonomus vis Clark, 1992 are described and illustrated, based upon specimens collected in the Serra de São José, Tiradentes, in Minas Gerais, southeastern Brazil. The species was previously known from the type series collected in the states of Amapá and Pará. Comparisons with the larva and pupa of A. grandis Boheman, 1843 and A. monostigma Champion, 1903 are included. The larvae of A. vis live as inquilines in the galls induced by a species of momphid moths (Lepidoptera, Momphidae) in the stems of Leandra aurea (Cham.) Cogn. (Melastomataceae).

Woody Gall symptoms in different citrus species and varieties artificially colonized by the citrus brown aphid Toxoptera citricidus

Seedlings of 41 different citrus species and varieties were massively colonized with the citrus brown aphid Toxoptera citricidus, obtained from Pêra sweet orange (Citrus sinensis) trees, presenting symptoms of the "Capão Bonito" complex of the Citrus tristeza virus (CTV). The objective was to evaluate resistance or tolerance of the varieties to that virus complex, but even after eight months of inoculation no stem pitting was observed in the plants. Otherwise, the presence of galls similar to those induced by the vein enation-woody gall disease was observed in 73% of the plants of Volkamer Palermo (Citrus volkameriana), 60% of the Volkamer Catania 2, 2% of the Rangpur Lime D.22.30 (Citrus limonia), 13% of the Volkamer Australian Red, the Rangpur Lime hybrid, the Orlando tangelo (Citrus reticulata x Citrus paradisi) and the Florida Rough lemon (C. jambhiri), and 7% of the Carrizo citrange (Poncirus trifoliata x Citrus sinensis). The highest incidence and the largest gall size were observed in the Palermo Volkamer showing that this clone would be the most suitable to be used as an indicator plant in biological indexing tests for the disease. There are no previous reports in the literature about the occurrence of woody galls in Orlando tangelo and Carrizo citrange.

Anatomia de galhas de ambrosia em folhas de Baccharis concinna e Baccharis dracunculifolia (Asteraceae)

Galhas de ambrosia são induzidas por dípteros (Cecidomyiidae) e desprovidas de tecido nutritivo, pois a larva do indutor alimenta-se de hifas de fungos. As galhas de ambrosia de Baccharis concinna e B. dracunculifolia são constituídas por uma única câmara larval, contendo um indutor. São observadas hifas de fungos. Nas galhas de B. dracunculifolia, as hifas ficam confinadas à câmara larval e as células do parênquima paliçádico mostram-se alongadas. Nas galhas de B. concinna, as hifas estão presentes também entre as células do clorênquima situadas ao redor da câmara larval. As células do clorênquima próximas à câmara larval alongam-se ligeiramente. As fibras pericíclicas do sistema vascular, em ambas as galhas, perdem as paredes secundárias. Quando o indutor está em fase pupal, as hifas de fungos aumentam em quantidade e preenchem várias partes da câmara larval. Nas hifas da galha de B. concinna verifica-se a presença de glóbulos lipofílicos, que estão ausentes nas hifas das galhas de B. dracunculifolia. Picnídios são observados somente nas galhas senescentes de B. dracunculifolia. Este trabalho é a primeira contribuição ao conhecimento de galhas de ambrosia na flora brasileira.

Elimination of biliary stones through the urinary tract: a complication of the laparoscopic cholecystectomy

The introduction and popularization of laparoscopic cholecystectomy has been accompanied with a considerable increase in perforation of gallbladder during this procedure (10%--32%), with the occurrence of intraperitoneal bile spillage and the consequent increase in the incidence of lost gallstones (0.2%--20%). Recently the complications associated with these stones have been documented in the literature. We report a rare complication occurring in an 81-year-old woman who underwent laparoscopic cholecystectomy and developed cutaneous fistula to the umbilicus and elimination of biliary stones through the urinary tract. During the cholecystectomy, the gall bladder was perforated, and bile and gallstones were spilled into the peritoneal cavity. Two months after the initial procedure there was exteriorization of fistula through the umbilicus, with intermittent elimination of biliary stones. After eleven months, acute urinary retention occurred due to biliary stones in the bladder, which were removed by cystoscopy. We conclude that efforts should be concentrated on avoiding the spillage of stones during the surgery, and that no rules exist for indicating a laparotomy simply to retrieve these lost gallstones.

Arthropods obtained from the Amazonian tree species "Cupiuba" (Goupia glabra) by repeated canopy fogging with natural Pyrethrum

Two canopies of a widely distributed Amazonian tree species, Goupia glabra Aubl. (Celastraceae, height 38 and 45m) were fogged several times with 1% natural pyrethrum during the rainy and dry seasons (1991-1994) in the Adolpho Ducke Forest Reserve near Manaus/Brazil. Between 50 and 158 ind./m2 of arthropods were obtained per tree and fogging event. Hymenoptera, mostly Formicidae, and Diptcra dominated. A total of 95 ant species occurred on a single tree. Most ants were permanently foraging in the canopy and their recolonization after fogging seems to follow stochastic pathways. Data indicated an interaction between - 1) predating Formicidae and gall building Cecidomyiidae and - 2) Cecidomyiidae and the parasitic Hymenoptera.

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.

A new species of Schizomyia (Diptera, Cecidomyiidae, Asphondyliini) associated with Tetrapterys phlomoides (Malpighiaceae)

Schizomyia maricaensis sp. nov. is described and illustrated based on the pupa, male, female, and gall. This species induces rosette galls on Tetrapterys phlomoides (Malpighiaceae).

New species of Lopesia (Diptera, Cecidomyiidae) associated with Eichhornia azurea (Pontederiaceae) from Brazil

A new species of gall midge, Lopesia eichhorniae sp. nov. (Cecidomyiidae, Diptera), associated with rhizomes of Eichhornia azurea (Sw.) Kunth (Pontederiaceae) is described. This is the first record of Lopesia galls in this species of macrophyte, quite common in natural and artificial lakes in Southeast Brazil. Illustrations of the adults (male and female), pupa, larva, and gall of the new species are presented.

Carcinoma metastatico do baço

Among the material of the archives of the Pathological Section of the Oswaldo Cruz Institue (Rio de Janeiro, Brasil) we found 9 cases of cancer metastasis in the spleen. Four of them were macroscopically apparent, but five had only been diagnosed microscopically. Of these cases of tumors, 3 are adenocarcinoma originated from the pancreas (cases 1, 3, 5,); 3 are primary carcinoma of stomach (cases 7,8 and 9); 1 adenocarcinoma of gall-bladder (case 2); 1 originated form the mammary gland (case 4) and finally 1 form the colon. (case 6.). The incidence of the metastasis observed in the spleen among the total of 6.400 studied autopsies is of 0,14%; The same incidence among those of epithelial blastomata is of 1,8%.

Redescription of Prosthenhystera obesa (Diesing, 1850) (Callodistomidae, Digenea) with New Host Records and Data on Morphological Variability

Prosthenhystera obesa (Diesing,1850) Travassos, 1922 from the gall bladder of Astyanax bimaculatus, Caranx gibbosus, Galeocharax humeralis, Leporinus copelandii, Pimelodus fur, Pseudopimelodus roosevelti, Salminus brevidens, Salminus maxillosus and from the new hosts, Cynopotamus amazonum and Triurobrycon lundii is redescribed, demonstrating a large morphological variation, mainly in body and testes size and shape. New hosts harbouring immature specimens of P. obesa are presented: Brycon sp., Leporellus vittatus, Pachyurus squamipinnis, Pimelodus clarias, Pseudoplatystoma corruscans and Salminus hilarii. Scanning electron microscopy micrographies, original figures and measurements of adult and immature specimens from different Brazilian hosts and localities are presented

Some coccidial parasites of the lizard Amphisbaena alba (Reptilia: Amphisbaenia: Amphisbaenidae)

Five parasites are described in the lizard Amphisbaena alba (Amphisbaenidae) from the state of Pará, North Brazil. Mature oocysts of Choleoeimeria amphisbaenae n. sp., are passed already mature in the faeces. They are ellipsoidal-cylindrical, average 33.7 x 22.8 µm and are devoid of micropyle, oocyst residuum or polar body. The colourless wall is smooth and of 2 layers. The 4 dizoic sporocysts have no Stieda body and average 13 x 9.3 µm. Endogenous stages develop in the epithelial cells of the gall-bladder in the manner described for the genus and may cause extensive tissue damage. Sporulation of Isospora capanemaensis n. sp., is completed 3 days after the oocysts are voided in the faeces. They average 14.8 x 14.5 µm and have no micropyle, oocyst residuum or polar body. The 2 tetrazoic sporocysts are pear-shaped, average 8.6 x 6.6 and have an inconspicuous Stieda body. Endogenous development is in the epithelial cells of the ileum, and heavy infections cause considerable tissue destruction. Multisporocystic oocysts passed in the faeces of one A. alba possibly originated from an invertebrate host ingested by the lizard. A globidium-like cyst in the digestive tract of A. alba measured 105 x 85 µm and contained many hundreds of merozoites. A stained kidney smear of the same lizard revealed the presence of an unidentified parasite producing multinucleate cyst-like stages.