Action de l'ecdystérone sur l'apolysis et l'ecdysis de divers crustacés isopodes

Ecdysterone acts differently according to the period of the moulting cycle when it is applied. In period C it induces apolysis, while at the beginning of apolysis it delays ecdysis. Experiments show that the exoskeleton cannot be rejected in the presence of ecdysterone. The possibility of stopping exuviation or ecdysis with ecdysterone seems to prove that this phenomenon is controlled by a particular factor called the factor of exuviation or the ecdysis factor. Ecdysterone would control only the release of this specific factor but would not prevent its action.     

13C NMR des alcaloïdes des Strychnos: Les dérivés de l'harmane et de l'usambarensine

¹³C NMR spectra of some tertiary and quaternary indole alkaloids are recorded and the signals assigned. Graphic interpretation of off-resonance spectra and substituent shielding effects together with the effect of N_b-methylation are utilized in the spectral interpretation.     

Réflexions critiques sur l'écologieet la systématique des Lingules actuelles et fossiles

New topics on ecology and systematics of recent and fossil Lingulids lead to an obvious revision of our knowledges on this zoological group. At first, the recent species need systematics and taxonomy on the bases of new described specific criteria (as, morphology of deltidial areas, muscle disposition); the results are briefly indicated. But, in fossil species, disorder and disparity of used characteristics are emphasized.The general conceiving on ecology of Lingulids are reviewed and discussed, especially on bathymetry and salinity; sediment and oxygenation conditions; taphocoenosis and lingulid «communities. On recent species, all these points are also studied, especially some ecological requirements (salinity, bathymetry, grain size), and mechanism of burrowing ability, burrow living positions in the sediments, as shell preservations after death and fossilization, to facilitate the paleobiotope interpretations. Recent animals are euryhalin, surviving at salinities from about 13 to 42‰; they could be considered as well adapted to waters with strong salinity fluctuations. They show preference to fine sand bottoms (lowest particle size about 40–60 μm). Their bathymetric distribution occurs between 0 and about 500 m (Lingula especially between 5–50 m; Glottidia 15–70 m). The isotherms 8–10°C seem to restrict their geographical and bathymetric distribution.Therefore, some post-palaeozoic lingulid bedsare studied or redescribed on the bases of the above discussed characteristics, and new interpretations on the environmental situation are given (Trias of Vosges Mountains; Oligocene from Japan; Eocene of London Basin). More caution must be used in study of fossil Lingulids that are not especially animals living in infralittoral bottoms with low salinity and deficient oxygenation, as generally accepted.     

Relation métabolique entre l'arginine et l'acide γ-aminobutyrique dans le fruit de Castanea sativa: étude préliminaire de l'arginase

Analysis of the free amino acid pool in the chestnut fruit (Castanea sativa) shows that it is high in γ-aminobutyric acid. A metabolic connection between arginine and γ-aminobutyric acid is evident. Three enzymatic activities are involved: L-arginine ureohydrolase, L-ornithine 2-oxo-acid aminotransferase and L-glutamate carboxylyase.     

L'âge du complexe récifal des côtes de meuse entre verdun et commercy et la stratigraphie de l'oxfordien dans l'est du bassin de Paris

The question of the age of «Hauts de Meuse coral rag is studied again using new faunas of brachiopods and ammonites collected above, below and inside the coral rag. Ammonites fauna of the well known «Calcaires de Creuë is revised. Results obtained agree closely.The «Hauts de Meuse coral rag grew up during Middle Oxfordian time; and extend part of the Plicatilis zone (Antecedens Subzone) and the whole Transversarium Zone up to the basis of the Bifurcatus Zone, for the first time identified in Lorraine. So it span a short depositional time, about 1 MY, with a high deposition rate, the thickness of the coral rag being more than 100 meters, reaching 150 meters in Saint-Mihiel area. Towards SE, on the other side of the Marne Gap, the sudden change into basinal facies go with a reducing of thickness and deposition rate.Upper Oxfordian deposits show a relative uniformity of facies and thickness. At the top of Middle Oxfordian limestones, the age of the discontinuity and the Sequanian renewal of deposition is basal Bifurcatus Zone. Erosional renewal and terrigeneous deposits are a wide spread event by the beginning of Upper Oxfordian.In the paleontological part, species upon which are based new ages and interpretations are only figured, except the species new or with new paleontological data, which are described. Type specimen of Perisphinctes mosensisBayle, from the «Calcaires de Creuë, is described and photographically figured for the first time.     

Analyse biostratigraphique et paléontologique de l'Albien marin d'Estremadura (Portugal)

The marine Albain from Estremadura is splited up into four Orbitolinidae zones, adjusted to biostratigraphic scales from mesogean province: zone with Orbitolina (Mesorbitolina) minuta (lower to middle Albian); zone with Neorbitolinopsis conulus (base of upper Albian); zone with Orbitolina (Orbitolina) concava (top of upper Albian) and zone with Orbitolina (Orbitolina) duranddelgai (Vraconian). The vertical extension of the main fossils is replaced in the framework of these zones. The most interesting species for biostratigraphy, paleoecology or taxinomy are summarily described.     

La sculpture et l'infrastructure du sporoderme de Ginkgo biloba comparées à celles des enveloppes polliniques des cyccadales

The Ginkgo biloba sporoderm, when examined with transmission and scanning electron microscopes, shows a sculpture and a texture which are very different from those observed in cycads.The ornamental units are “rugules” which are evenly disperesed over the pollen grain surface except on the germinal zones which is decorated with “verrucoïde” components mixed with a few ridges. (2) The exine is composed of a tripartite sexine, the middle zone of which is full of irregular pits, and of a thick and strongly lamellated nexine.     

Stabilité de l'espèce et évolution: La théorie de l'équilibre intermittent («Punctuated equilibrium)

Paleontologists' traditional conceptions on evolution do not seem to be in perfect accord with these of biologists. The gradual phyletism is compatible neither with E. Mayr's model of the Founder, nor with the actual stability of most of the paleontological species. The punctuated equilibrium model proposed by N. Eldredge & S.J. Gould offers a solution which integrates both paleontological observations and the data of modern biology.     

A propos des fossiles du Pliocène d'Aguilas(Sud d'Almeria,Espagne) découverte de Cirripèdes operculés (Crustacés) et discussion sur l'étho-écologie des formes épizoaires

A benthic taphocoenose from the Pliocene I of Aguilas (provinces of Murcia-Almeria, Southern Spain) conseals four Cirripedia (family of BalanidaeLeach): Balanus (Balanus) perforatus angustusGmelin, B. (B.) amphitriteDarwin, B. (Megabalanus) tintinnabulum tintinnabulumLinné and Creusia (Withersia) phryxaPajaud.The study of the last one is especially interestingfrom an ecological point of view. Indeed, all species, well-known in the Creusia-Pyrgoma group are more or less dependent on Anthozoa since Miocene, the cuplike basis of their shell buried on corallites. But not corallites were gathered in the deposits of Aguilas and the morphology of Creusia phryxa leads us to believe a fixation of the shell on a flaccid substratum. From which we may suppose that the host of this Cirriped was perhaps an Actiniaria.     

Action de l'antimycine a sur l'activité succinoxydase des mitochondries du tubercule de Pomme de Terre,et comportement des cytochromes de type b

A kinetic study of the effect of antimycin A on succinate oxidase from plant mitochondria produced sigmoidal curves for the reduction of cytochromes b₅₆₀ and b₅₈₅ and for the inhibition of succinate oxidase. In the stationary state the interaction of the various components of the respiratory chain (flavins, ubiquinone, cytochromes…) occurs in a sequential mode which allows the application of simple equations utilizing rate constants and cytochrome concentrations. In these equations, it is assumed that there exists an excess of ubiquinone relative to other components of the respiratory chain as suggested by Kröger & Klingenberg (1970) and that the reoxidation of b cytochromes is fast. The inhibition by antimycin A, characterized by non-linear inhibition curves for succin-oxidase and inhibitor fixation in complex III on a component other than cytochrome c₁, is interpreted in terms of this model. This hypothesis presupposes the existence of an F factor between cytochrome b₅₆₀ and cytochrome c₁ as suggested by other authors. Utilizing these equations, theoretical curves for the inhibition of the reduction of cytochrome b₅₆₀ have been constructed and the results agree with the experimental data. The kinetic behavior of cytochrome b₅₆₆ during the induction of anaerobiosis suggests that it is not directly involved in the electron transfer chain but rather is either in thermodynamic equilibrium with cytochrome b₅₆₀ or in a shunt between cytochrome b₅₆₀ and factor F. From the experimental data, an equation is derived for the inhibition of the reduction of cytochrome b₅₆₆ by antimycin A. The actual effects of ATP and mClCCP on succinoxidase agree well with those predicted by the model.     

Purification de l'alcool deshydrogénase de tomate par chromatographie d'affinité

Tomato alcohol dehydrogenase has been purified 99-fold by affinity chromatography on Blue Sepharose CL-6B with 37% yield. The enzyme so obtained is homogenous in polyacrylamide gel electrophoresis. By adding 20% glycerol to the extraction and purification buffers, an enzyme is obtained which is stable for several months at 4°. The molecular weight values determined by gel filtration (Sephadex G 200) and polyacrylamide gradient gel electrophoresis on one hand and by polyacrylamide gel electrophoresis in sodium dodecyl sulfate on the other, show that the enzyme exists in dimeric form.     

Echinodermes (Homalozoa: Cornuta et Mitrata) nouveaux pour l'Ordovicien du Massif Armoricain et conséquences paléogéographiques

Two specific genera of Bohemian Llanvirn(Sarka Formation), Reticulocarpos and Lagynocystis have been recognized in Traveusot, le Pissot and Pierre Melière Formations (Llanvirn and Llandeilo of the Armorican Massif). Though three species are new (R. pissotensis, R. sp., Lagynocystis sp.) this discovery once more underlines the relationships between Bohemia and Armorican Massif during this period.     

Scolécodontes,assemblage et appareil de vers annelidespolychetes errantes de l'aptien de la région d'Agadir,Maroc

From the Aptian scolecodonts inventory of the Agadir area one jaw apparatus and one joining of polychetes are reconstructed. One is the elementary species Schistomeringos expectatusSzaniawski & Gazdzicki, 1978, the oldest representative of the multielementary family Dorvilleidae Chamberlin 1919. The other is a representative of either the multielementary families Atraktoprionidae Kielan Jaworowska 1966 emend. Kozur, 1970 or Arabellidae Hartman 1944. This joining is considered as an hypothesis since all the necessary criteria, defined by H. Szaniawski & A. Gazdzicki 1978, are not all present.     

'Etude comparée des genres Babinka Barrandeet Coxiconcha Babin (Mollusques Bivalves de l'Ordovicien) intérêt phylogénétique

The comparative examination of two genera ofMollusca Bivalvia from the Lower Ordovician, Babinka and Coxiconcha, reveals some affinities between them. Their similarities are relating to the arrangement of the muscle scars; the dentitions are, on the contrary, rather unlike; a similar origin might nevertheless be advanced. It is pointed out that Coxiconcha seems, moreover, to be a primitive Modiomorphid. These new data allow to perfect the previous phylogenetic sketches and consequently to correct the classification, making obvious the outstanding part of the Actinodontoids in the diversification of the Mollusca Bivalvia during the Ordovician.     

Modalités d'installation et d'évolutiondes Harpocératinés (ammonitina A) au Domérien inférieur dans le sud-Ouest de l'Europe (France,Portugal)

In Mesogea, the Harpoceratinae were known asearly as the end of the Lower Carixian. They later reached the sub-boreal province through the Alps or the South of the Iberic Peninsula. The analysis of the populations met in four crosssections of the Lower Domerian (Causses, Mâconnais, Franche-Comté, Portugal) showed the settling down of the Protogrammoceras isseli group that set up and evoluated in a similar way in the different areas in spite of a certain originality.On the one hand, it gave the cladogenetic groupP. monestieri-nitescens by diminution of the ribing density, strengthening of the ribs and simplification of the suture.On the other hand, a slower evolution give, near the end of the Stokesi zone, P. normanianum in the Paris Basin and in Burgundy, and P. lusitanicum in Portugal. At the same time, a new invader, P. celebratum, arrived in the Causses (and in Portugal).     

L'action exercée par l'appareil endocrine sur les phases tardives de l'ovogenèse chez Locusta migratoria

Most studies dealing with the endocrine control of oogenesis are focused on vitellogenesis, but the later events of oogenesis: vitelline membrane formation and choriogenesis have received less atention. In Locusta migratoria, the corpora allata evidently control vitellogenesis, but seem to have no bearing upon the formation of the vitelline membrane or the chorion. If the insects are deprived of their CA at the time when the oocyte length is around 3.5 to 4 mm, (normal length at egg laying: 6.5 mm) vitelline membrane formation and the chorion production are unaffected. In the same species, the electrocoagulation of the pars intercerebralis or excision of corpora cardiaca disturb oogenesis; vitelline membrane material is synthesized and secreted, but the primary granules fail to join each other and to transform into vitelline membrane and the production of chorionic material is disturbed.The rER of the follicle cell seems quite active but the substance elaborated accumulates in the Golgi saccules, and therefore the cytoplasm contains only very few secretory granules. The implantation of supernumerary pars intercerebralis and corpora cardiaca into immature females induces precocious deposition of the vitelline membrane which is complete in 5.0 mm oocytes (instead of 5.6 to 6.0 mm) and chorion formation is completed in 5.5 mm oocytes (instead of 6.0 to 6.3 mm). Ecdysone is secreted in the ovaries at the end of oogenesis. We tested the result of injecting ecdysone to immature females. It results in hastening oocyte growth during 24 hr, but this accelerated growth is followed by degeneration.     

Ultrastructures nouvelles et non identifiées dans les calcaires de l'oxfordien supérieur de la champagne berrichonne

A scanning microscope study of the upper Oxfordian foliated limestones of the western part of the Berry region of France has revealed new, but unidentified, well-conserved organisms, which are described and illustrated in this publication.