Ultrastructures tegumentaires chez un crustace copepode cletocamptus retrogressus

The cuticle, the epidermis, the cross-striated muscle cells, their attachments and some sensory endings of this planctonic Crustacean, have been observed and are briefly described. The twisted system and the differentiation of hexagonal patterns have been studied with the electron microscope, mainly in the outer levels of the procuticle. Comparisons with other Cuticular patterns and with physical systems are discussed.     

Sur un effet de groupe chez les femelles deCamponotus vagus (Scopoli)

Résumé L'élevage en nids artificiels identiques de jeunes femelles fécondes deCamponotus vagus a fait apparaître un effet de groupe élémentaire chez les femelles associées, se traduisant par une activation prononcée de la production du couvain, comparativement aux femelles isolées. Des recherches futures auront à préciser la nature des stimulations en jeu.

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Zusammenfassung Zuchtversuche in künstlichen und identischen Nestern von Ameisenweibchen der ArtCamponotus vagus liessen einen elementaren Gruppeneffekt erkennen indem zwei zusammenlebende Weibchen eine erhöhte Lege-und Brutpflegetätikeit entwickelten im Vergleich zur Sùmme dieser Tätigkeiten von zwei einzellebenden Weibchen. Weitere Untersuchungen haben die Natur der dabei auftretenden Sinnesreize zu klären.

     

Deux cas de Rhinosporidiose nasale chez une oie et un canard sauvages a Astrida (Ruanda-Urundi)

Conclusions Les auteurs relatent la découverte à Astrida de deux cas de rhinosporidiose nasale chez des anatidés très répandus en Afrique centrale: l'oie d' Egypte et le petit canard siffleur africain.Les lésions observées consistent en polypes des fosses nasales. Histologiquement ces polypes correspondent à des granulomes et leur structure est dans les grandes lignes identique à celle qu'on observe dans les lésions de rhinosporidiose nasale chez l'homme.Le parasite observé dans les lésions est morphologiquement identique àRhinosporidium seeberi, l'agent causal de la rhinosporidose chez l'homme.Les auteurs envisagent les conséquences de cette découverte au point de vue de l'épidémiologie de la rhinosporidiose humaine.     

Geotrichum pseudocandidum n. sp., isolé chez un Cerf d'Eld — Rucervus Eldi (Guthrie)

Summary A new fungus was isolated from the stomach of aRucervus eldi (Guthrie) which died less than 24 hrs after birth in the Paris Zoo. It is described as the new speciesGeotrichum pseudocandidum. It can be differentiated fromG. candidum by the fact that it does not assimilate mannitol.     

Rythme d'activité endogène chez un nébaliacé (Crustace phyllocaride)

In constant conditions and continuous darkness, the burrowing species Nebalia bipes (Fabricius) exhibits a clear circadian rhythm of emergence from the substratum and of swimming activity. The rhythm, in which activity occurs during the ‘expected night’, is obvious in both males and females and can remain overt for several weeks.The ‘free-running period’, although variable, is ≈ 24 h 20 min in a calm environment and at 18 °C. During the first day of the experiments, the swimming activity of freshly collected animals increases abruptly at dusk and then decreases gradually towards dawn. It has been possible to change the phase of the rhythm by subjecting the animals to a reversed LD schedule.The synchronization seems to result from the high photonegativity of Nebalia in normal daylight. The results of some experiments carried out with young juvenile animals suggests that the synchronization may possibly take place during the incubation period.     

A propos de la presence d'un “canal spiral”chez Daxia CUVILLIER & SZAKALL (Foraminifera,Lituolidae)

The presence of a spiral channel within the external marginal part of the whorls of Daxia CUVILLier &0611 SZAKALL, described by B. Laug & B. Peybernès, cannot be confirmed. The generic attribution of “D”. minima LAUG & PEYBERNES is not yet clear.     

Manifestation d'un comportement territorial chez les crevettes pontoniinae associées aux mollusques pinnidae a tuléar (Madagascar)

Shrimps associated with molluscs are generally found in pairs in their host and observations show that this disposition leads to active competition, both intra- (between individuals of same sex) and interspecific.The territory in dispute is the entire palliai ensemble of the mollusc. The weapons are the second pair of pereiopods and their size is of prime importance in determining the outcome of any encounter.In interspecific confrontations, Paranchistus ornatus Holthuis is regularly expelled by Anchistus custos (Forskål), and Conchodytes biunguiculatus (Paulson) will displace both of these species.     

Mise en evidence d'un dispositif structural nouveaude la coquille des brachiopodes chez “Rhynchonella” CF. Phaseolina DESL. (Rhynchonellida-Jurassique)

New features are detected on the marginal edges of the valves of rhynchonelloid brachiopods belonging to the“Rhynchonella” phaseolina DESL. and Parvirhynchia minuta (BUV.) group. They are described as hinge pouchs and commissural grooves on the shell of “R.” cf. phaseolina, a new found member of the group from the lower Bathonian of Nièvre (France). Fonctionnal, ontogenetic and taxinomic implications must be considered.     

Les etapes de la vitellogenese chez Thermobia Domestica (Packard) (Thysanura: Lepismatidae)

Study of the ultrastructural modifications of the follicular epithelium and of the oocytes during the high growth period of the terminal follicles has allowed us to characterize 4 successive phases and to pin-point their synchronisation with the moulting cycles in adults. During phase 1, which takes place near the end of a moulting cycle, the terminal oocytes still undergo previtellogenic growth, followed by the beginning of micropinocytosis and vitellogenesis (lipid droplets at first, then little protein granules), whereas the follicular cells remain joined together. The 2nd phase starts a little before ecdysis; this phase and the third one correspond to 2 steps of intense vitellogenesis, with simultaneous deposition of lipid and glycoprotein. Endogenous protein synthesis seems to be very limited, unlike most other Apterygota. The follicular cells gradually differentiate proteosynthetic organelles, but continue dividing; the intercellular spaces become greatly distended during the 2nd and 3rd phases. Vitellogenesis can be completed only if insemination takes place at the beginning of each moulting cycle. The 4th phase is marked by the formation of the vitelline envelope and of the chorion, while the follicular cells, once more joined together, become very flat and poor in organelles. Oviposition takes place in the middle of the intermoult period.     

Une glande épidermique ventrale chez les larves deAcromyrmex octospinosus (Reich) (Hymenoptera-Formicidae)

Insectes Sociaux - Une glande de type I, selonNoirot etQuennedey (1974), est signalée chez les larves deAcromyrmex octospinosus (Reich). Cette glande se présente sous la forme d'un...     

Polymorphisme biochimique chez le faisan commun (Phasianus colchicus)

Egg white proteins, hemoglobin, serum proteins and enzymes from Phasianus colchicus have been examined by starch gel electrophoresis. All three genetic parameters, mean proportion of loci polymorphic per population (P), mean numbers of alleles per locus (A), and mean proportion of loci heterozygous per individual (H), are given. Comparison were made between the proteins of the related species Coturnix coturnix japonica, and the variation of pheasant proteins is discussed in connexion with the genetic structure of the population studied.     

A cytogenetic survey of 110 baboons (Papio cynocephalus)

A cytogenetic investigation of 110 adult baboons (Papio cynocephalus) captured in Kenya and sacrificed at the Institut Pasteur, Paris, showed the absence of anomalies, numerical or structural bearing on nonheterochromatic material; a polymorphism of the AgNOR-positive secondary constriction of chromosome 5 in 12% of the animals; a polymorphism of a secondary constriction of chromosome 7 in 2% of the animals; a fragile site of chromosome 6 in one animal. We believe that our data show that cytogenetic observations in present day primates probably reflect their chromosomal evolution.