Figuration et complements de diagnose d'Acrocoelites bobeti Lissajous,belemnite du Lias superieur Français

In 1925 then in 1927, a new species of Belemnite: Acrocoelites bobeti, was mentioned and described without any figuration by F. Roman (M. Lissajous's posthumous work and notes).This species is here pictures and its diagnosis is completed owing to the rediscovered samples of M. Lissajous and to a hundred specimens found in the Lias of the western slope of the Balduc Mount, in the village of Saint-Bauzile (Lozère). Thin sections made into several phragmocones level with the siphon have alloved to give precisions on that species.     

Structure et fonctionnement des écosystèmes du Haut-Rhône français

Many abandoned stream channels are provided alternatively by river water or groundwater from the interstitial flow. The cyclopoid populations from an abandoned channel of the Rhône river are compared with those from a neighbouring interstitial station. Among the 18 species of cyclopoids found during the present study, only 4 are common to both stations. During 3 years of sampling, the populations living in interstitial waters were rather stable, while the epigean populations were more fluctuating. The latter seem to be influenced by the origin of the water.     

Une dent d'aspect mammalienen provenance du Rhétien Français

This paper analyses a tooth with mammal-likecharacters found in the lower Rhaetian of Lorraine. The comparison of this specimen with teeth of therapsid cynodonts and contemporary mammals has not led us to assimilate it to any previously known form, but suggests a relationship with late and advanced cynodonts, and allows us to place the animal at the reptilian-mammalian transition. This is the first indication of a therapsid in France.     

Revue critique de la mycologie medicale entre 1946 et 1956 en France et dans l'Union Française

Sans résumé     

L'indice thermique,un essai de méthodepour comparer et utiliser climatologiquement les gisements quaternaires. Application aux oiseaux du Pléistocène Français

The birds found in the Middle and Upper Pleistocene sites of France can be classified in four categories according to the thermic requirements of present forms. A «guide-number growing from 1 to 4 and corresponding to an increasing temperature has been ascribed to each category. The «Thermic index is calculated from this guide-number and takes into account the relative frequency of species.The different values obtained for the main fossilavifaunas allow to find climatic fluctuations that, in the whole, confirm the facts already known, which therefore allows to test the method.     

Sur l’extinction des populations avec plusieurs types dans un environnement aléatoire

This study focuses on the extinction rate of a population that follows a continuous-time multi-type branching process in a random environment. Numerical computations in a particular example inspired by an epidemic model suggest an explicit formula for this extinction rate, but only for certain parameter values.     

Facteurs de limitation des populations d'Aphis fabae dans l'ouest de la France III. Répartition et incidence des différentes espèces d'Entomophthora dans les populations

Résumé Plusieurs espèces d'Entomophthora participent à la régulation des populations d'Aphis fabae Scop. sur féverole dans l'Ouest de la France. Les r?les respectifs de chaque espèce ont été évalués en 1971 et de 1973 à 1975. Entomophthora fresenii Nowak. est l'espèce qui se dissémine le plus rapidement et le plus complètement dans les parcelles, et qui est la plus agressive au niveau des colonies. Ces deux caractères en font l'agent pathogène dominant d'A. fabae dans l'Ouest, 3 années d'observations sur 4.Entomophthora aphidis Hoffman, bien que présent tous les ans n'est le pathogène le plus efficace qu'en 1973.Entomophthora thaxteriana Petch etEntomophthora planchoniana Cornu n'apparaissent pas chaque année et, lorsqu'ils sont présents, n'interviennent que pour une faible part dans le développement des mycoses. Des facteurs inhérents à l'agent pathogène (spécificité, caractères du cycle) ainsi que des facteurs écologiques (climatiques) sont évoqués pour expliquer la prédominance d'E. fresenii.

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Summary Several species ofEntomophthora take part in the natural control ofAphis fabae Scop. on field beans (Vicia faba) in the West of France. The respective importance of each species was assessed in 1971 and from 1973 to 1975. Entomophthora fresenii Nowak. is the species that most completely and quickly spreads in the fields, and the most efficient in the colonies. For both reasonsE. fresenii is the main pathogen ofA. fabae in the West of France 3 years over 4. AlthoughEntomophthora aphidis Hoffman occurs every year, this species was the most efficient pathogen in 1973 only.Entomophthora thaxteriana Petch just occurred in 1974 and 1975 and, these years, its contribution in the total sum of infected aphids was low.Entomophthora planchoniana Cornu appeared in 1975 only, very late in the season, which makes its pathogenicity difficult to assess. Factors inherent to the pathogen (specificity ofE. fresenii, nature of its cycle, dependence of the aggregation of aphids) and ecological factors such as response to climate variations, may at least to a great extent explain the predominance ofE. fresenii. All these factors must be studied for a good understanding of this species.

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Les 2 premiers mémoires de cette étude ont été publiés dans Entomophaga respectivement parRobert et al. (18, 1973, 61–75) etRabasse & Robert (20, 1975, 49–63)     

Le genre Postepithyris makridin (térébratulidés,brachiopodes) dans l'oxfordien et le kimméridgien Français

The questions relating to the type-species of genus PostepithyrisMakridin and to its systematic position within Terebratulids are discussed.The French species are described: besides the type-species P. cincta (Cotteau) from Upper Oxfordian, two species from Inferior Kimmeridgian can be included in this genus: P. minor (Douvillé) and P. dubisensis nov. sp.A new subspecies P. cincta mosensis nov., recently discovered in Oxfordian from East of the Paris Basin, can also be assigned to the genus.Postepithyris did not evolve through a single special facies: the species could supported different environmental conditions.     

Influence du d?bit d'eau de mer dans un dispositif de culture ? fibres creuses dialysantes sur la croissance phytoplanctonique et 1'extraction des nitrates du milieu

It is demonstrated that the productive capacity of mass dialysisculture of phytoplankton is intimately related to the rate offlow of nutrient medium along the membrane. Comparison of culturesof Phaeodactylum tricornutum, subject to different medium flowrates (92 versus 250 ml.min^–1) during a 17-day growthperiod, reveals increased productivity (in terms of cell numbers,chlorophyll a, dry weight, cell nitrogen, cell carbon, ATP)at the higher flow rate. Differences are most pronounced inthe latter stages of growth (i.e., linear and stationary) attainingratios between 2 and 3 for cell nitrogen, cell carbon and ATP.Lower C/N ratios for the greater yielding culture translatesas enhanced osmotic diffusion as well as cellular assimilationof nitrates. The positive effects of increasing medium flowrate on phytoplankton growth result from improved dialyzer performancewith respect to low molecular weight solutes. This is evidencedin the proportionately greater values obtained for mass transferof nitrate-nitrogen. Accordingly, measures of nitrate clearanceindicate a progression from 29 to 85 ml.min^–1 in responseto augmenting sea water flow from 32 to 292 ml.min ^–1.The culture apparatus recently developed consists of a separatedialysis unit (a hollow-fiber cartridge used in hemodialysis)coupled to a temperature-controlled growth chamber. Culturesreceive a continuous flow of natural sea water and are grownin the batch dialysis mode. The main advantages of this methodrelate to its potential for large-scale, axenic algal culturebased on the abundant source of cheap nutrients that constitutesnatural sea water.     

Biométrie des graines et nombres chromosomiques dans la sous-sectionHeterophylla du genreCampanula (Campanulaceae)

Length measurements of seeds belonging to 12 taxa of theCampanula rotundifolia group, including six Pyrenean endemics, prove a certain relation between seed length and ploidy level (2x–4x–6x).

     

Changements de la structure du paysage et richesse spécifique des fragments forestiers dans le sud-est du Brésil

We used the Hallé and Oldeman's groups of the present and of the future, as obtained by an architectural analysis of trees, in order to test the hypothesis that the group of young (or potential) trees is more sensitive to parameters of present landscape structure than the group of old trees. The landscape structure and the tree species richness of 11 remnant forest fragments, located in the riparian corridor of the Jacaré-Pepira river (S.E. Brazil), were studied. The results showed that the tree species richness may not be linked to the landscape structure changes that have been occurring since 1962 (date of the oldest aerial photographs from the region). The studied communities are probably still responding to the main landscape structure changes that occurred during the second half of the 19th and the beginning of the 20th century as a consequence of the expansion of coffee plantations. Furthermore, the group of the future presented significant correlations with a greater number of landscape indices, confirming the initial hypothesis of greater sensitivity of the younger trees to the present landscape structure. It appears also that the richness of the group of the future is mainly affected by the present landscape structure while the richness of the group of the present results from interactions with present and past landscape structures.     

Les modalités du percher dans un assemblage de Scarabaeinae de la forêt de Guyane française

Le percher est un comportement répandu chez les espèces d’un assemblage de Scarabaeinae d’une forêt non perturbée de Guyane française. Quarante-trois espèces de percheurs ont été répertoriées sur 7 ans d’échantillonnage. Les fouisseurs diurnes de petite taille (moyenne 7,0 mm) dominaient sur les feuilles isolées et autour des défécations de Singes hurleurs ou des fèces humaines, avec une hauteur moyenne de percher de 62,8 cm. Les hauteurs étaient positivement corrélées aux tailles des insectes excepté pour cinq grandes espèces dont trois possédaient une défense chimique contre les prédateurs. Deux complexes mimétiques ont été identifiés. L’agrégation en dehors de la présence de ressource a été montrée. Les défécations de singes provoquaient une concentration d’insectes dont des Canthon (Glaphyrocanthon) arboricoles qui formaient leurs pilules sur les feuilles. D’autres espèces perchaient en attente de rencontrer au sol un partenaire ou de se livrer au kleptoparasitisme. Les signaux olfactifs pourraient jouer un rôle dans diverses modalités du percher. Compétition et prédation semblent être les principales contraintes auxquelles le percher répond.