La question des hétérochromosomes chez les Sauropsidés. I. Reptiles

Summary In contradiction to some Japanese authors (Oguma, Makino, Nakamura), we are unable to find any difference in the chromosome sets of the male and female ofLacerta vivipara (2N = 36). In a saurian, where the analysis is very easy (Chamaeleon bitaeniatus), there are, without the smallest doubt, 24 chromosomes in both sexes (20M + 4m). The evidence of a female heterogamety in turtles is by no means satisfying.     

Effets comparés de laβ-propiolactone et du formol sur les propriétés inductrices de l'organisateur chez les amphibiens

Summary -propiolactone-treated dorsal lips ofAmbystoma mexicanum are grafted in the blastocele of young gastrulas. The inducing ability of dorsal lips is not altered. These results are compared with the effects of formaldehyde which suppress the inducing ability. An interpretation of these facts is proposed. The cross-linking reactions which occur between formaldehyde and proteins may be important for the suppressing of the inductive ability by this agent.     

La biologie des hématinoprotéides oxygénables

Summary The author reviews a series of biological aspects of the study of oxygenable hematinoproteids, particularly with respect to evolution and adaptation. After a statement of some fundamental concepts of comparative biochemistry and of possible evolutionary relations between oxidation catalysts and oxygen carriers, the natural distribution of hemoglobins is reviewed and their specific characters are enumerated.A review is made of the data relating to the shape of the oxygen-dissociation curves and to the affinity of hæmoglobin for oxygen. It appears, generally speaking, that hyperbolic or almost hyperbolic curves and high affinity for oxygen are characteristic of primitive or embryonic hæmoglobins.A study of the function of hæmoglobin in the respiratory cycle of several animal species shows the vital importance of the oxygen carrier as well as the adaptation of the shape and position of the dissociation curve to the character of the respiratory function in the animal considered.The function of hæmoglobin in invertebrates, as oxygen carrier as well as providing a store of oxygen, is emphasized by a review of experimental data.The function of oxygen in the transport of carbon dioxide is reviewed from the standpoint of comparative biochemistry, and the lack of our knowledge is deplored.The characteristics of chlorocruorin show it to be a chemical mutation of an Annelid hæmoglobin.Our lack of knowledge in the field of the comparative biochemistry of hæmoglobin and chlorocruorin metabolism is pointed out.

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Conférence principale, présentée à la Société suisse de biologie médicale lors de la 127^e Assemblée générale de la Société helvétique des sciences naturelles à Genève, le 31 août 1947.     

L'évolution de la formule chromosomiale chez les Vertébrés

Sans résumé     

L'évolution de la formule chromosomiale chez les Vertébrés

Sans résumé     

Essai d'interprétation des résultats obtenus récemment chez les Vertébrés sur l'intersexualité hormonale

Sans résuméLaboratoire de zoologie et d'embryologie expérimentale de la Faculté des sciences de Strasbourg.     

Sur l'inhibition sélective des acétylcholinestérasesin vivo chez le chien

Summary 3318 CT [bis(piperidinométhylcoumaranyl-5) cetone diméthiodide] a compound recently synthesized byA. Funke andK. von Däniken, is shown to be a potent and selective inhibitor, bothin vitro andin vivo, of the blood acetyl-cholinesterase (AcChE) of the dog. It produces acetylcholinomimetic symptoms in the animal and sensitizes different responses to acetylcholine and to stimulation of cholinergic nerves without inhibiting the blood non-specific cholinesterase (XChE). However, the action of 3318 CT appears to be limited, both in nature and in intensity, when compared to that of prostigmine, although the latter substance is a less potent inhibitor of AcChEin vitro than is 3318 CT. This difference is probably related to many factors, one of which may be the fact that prostigmine inhibits not only AcChE but also XChE; and it is not yet ascertained that XChE plays no role at all in the limitation of the effect of the stimulations of cholinergic nerves.     

La pression intrarénale chez l'homme

Summary The intrarenal pressure has been determined in man using a needle of the lumbal puncture type connected with a mercury manometer. Preliminary results in 8 patients with various renal diseases indicate no significant difference between cases of glomerulonephritis, acute anuria, chronic pyelonephritis and normal or almost normal kidneys. Our values are comprised between 23.5 and 41.5 mm of mercury, with an average of 34 mm. A possible correlation with the mean blood pressure is suggested by our data: intrarenal pressure =0.19 mean blood pressure +9.0. In one case, renal decapsulation had no influence on the intrarenal pressure.     

La détermination expérimentale de la masse des mésotons par les méthodes d'ionisation

Sans résumé     

Inhibition de la cancérogenèse spontanée chez les souris R III et AkR par des implants de tissus cancéreux modifiés

Summary (1) After a 24-h passage in a rabbit, fragments of spontaneous isologous mammary carcinoma were implanted under the skin of young R III females. This procedure was found to prevent the appearance of spontaneous mammary tumours in a high percentage of these animals. The subsequent appearance of carcinoma was to be observed in only 23% of treated animals as compared with 51% in controls.(2) After a 24-h passage in a rabbit, fragments of leukotic isologous tissue, implanted subcutaneously in young AkR females, reduced subsequent spontaneous leukomogenesis from 85 to 38%.     

Propriétés phytobiologiques de la sérotonine

Summary The serotonin (5-hydroxytryptamin) which shows a slight influence upon the growth of plant tissues, acts upon water uptake by regulating cellular permeability (latter is activated in the case of K⁺).     

Remarques sur la note deS. Moeschlin:L'observation des granulations de Heinz dans les hematiés

Sans résumé     

Sur une nouvelle méthode chromatographique pour la séparation de composés polycycliques aromatiques ou hétérocycliques

Summary A new chromatographic technique is described, which makes use of the affinity of anhydrides and imides of tetrahalogenophthalic acids towards aromatic and heterocyclic polycyclic compounds. This method has been successfully applied to the resolution of some problems of analytical organic chemistry.     

L'endocrinologie des invertébrés

Sans résumé     

Colorants acides et détermination embryonnaire chez les Echinodermes

Summary The effects of three dyes with carboxyl groups are been studied on the developing eggs of the sea urchin,Paracentrotus lividus. Uranin and rose Bengal are both some derivative of the xanthene. Chrome violet CG is a carboxyl derivative of pararosolic acid. In dilute solutions these three dyes induce the development of radial larvae. At higher concentration, uranin and rose Bengal are very effective animalizing agents. Rose Bengal is more active than uranin. Rose Bengal differs from uranin by the fixation of halogens on the molecule of dye which increase the acidity of the carboxyl group. It appears that animalizing activity runs parallel with acidity. The results of these experiments are discussed in relation to the animalizing effects of various acid sulfonated dyes. The possible significance of the combinations between acid dyes and basic components of the cells in the animalization is considered.     

Un nouveau type de détermination chromosomique du sexe chez les mammifèresEllobius lutescens Th. etMicrotus (Chilotus) oregoni Bachm. (Muridés-Microtinés)

Summary (1)Ellobius lutescens andMicrotus oregoni show the same type of sex-chromosomes. The diploid number is odd in both sexes, seventeen.(2) The odd element ofEllobius is morphologically alike in the male and in the female. InM. oregoni, the odd element of the male is acrocentric, that of the female metacentric.(3) Following a hypothesis ofWhite, it seems very probable that the heterochromosome of the male is built of the primitiveY (short arm) and the primitiveX (long arm) linked together. In the female of the same species (M. oregoni), the sex-chromosome represents both theX fused together.(4) Only the half of the Zygotes may develope, the other half being lethal.(5) The close kinship betweenEllobius andM. oregoni is certain, a parallel evolution appearing as highly improbable.     

La glycolyse anaérobie au niveau des lobes optiques isolés de l'embryon de poulet

Summary A series ofin vitro experiments have been made on lactic acid production in anaerobiosis in the developing optic lobes (mesencephalon) of the chick embryo. The rate of anaerobic glycolysis is relatively important during multiplication of the neuroblasts; but, during the differentiation of the neuroblasts into mature neurons, the anaerobic processes are lower than the phosphorylation and oxidation mechanisms essential for the growth of nerve expansions and onset of functional activity.     

L'évolution de la symbiose chez les Isoptères

Summary An attempt is made to retrace the evolution of symbiotic associations in Blattopteroidea, with particular reference to Isoptera. It seems probable that double symbiosis occured in the common ancestor of Blattids and Termites: intracellular microorganisms of bacteriocytes, xylophagous intestinal Flagellates. Where as actual Blattids, exceptingCryptocercus, have only retained the former, the primitive Termites, exceptingMastotermes, have only kept the latter. Evolved Termites (fam. Termitidae) have in turn lost the symbiotic Flagellates, but have acquired a rich and complex bacterial flora. — Some of these microorganisms, mixed with their aliments, certainly aid digestion (breakdown of cellulose), whilst others, localised at a particular level of the alimentary canal and not found in the alimentary mass, presumably play a different rôle. Furthermore, Protozoa are constantly associated with certains Termites (xylophagous Amoebae, humus-feeder Ciliates of the genusTermitophrya) and may play some rôle in the process of digestion. Finally, an association occurs between fundgus-growing Termites (subfam. Macrotermitinae) and mushrooms (Termitomyces).