Deux fougères fertiles du Stéphanien du Massif Central (France)

Two fertile ferns from the Stephanian of the Massif Central (France) are described in detail. One has been found in the Blanzy basin and is assigned to Oligocarpia (Sphenopteris) leptophylla (Bunbury) nov. comb., according to the morphology of the sterile pinnae and of the fructifications. Its spores agree with the «sporae dispersae Granulatisporites parvus (Ibr.) Potonié and Kremp. The other fern has been collected in the St Etienne basin and is assigned to Senftenbergia plumosa (Artis) Radforth var. ligerensis nov. var. Its spores agree with the morphographic genus Raistrickia (S., W. and B.) Potonié and Kremp but do not look like any described species; therefore the new species name R. polymorpha nov. sp. has been given to that spore.     

Isorthid AE (Brachiopoda) du dévonien inférieur du massif armoricain

Three species of Isorthidae are described in the Lower Devonian of the Armorican Massif. Two of them were hitherto badly known, being never adequately described nor figured: Isorthis (Protocortezorthis) miloni from the Gahard Formation (Gedinnian) and Isorthis (Protocortezorthis) trigeri from the Saint-Céneré Formation (Gedinnian-Siegenian). Isorthis oehlertiSolle, 1976 is considered as a synonym of Isorthis (Protocortezorthis) trigeri. The geographic distribution of these species allows to corroborate that until the top of the Lower Devonian (top of Le Faou Formation), two provinces with different faunal associations exist in the Armorican Massif.     

Ultrastructure du mucus (cellules caliciformes du côlon) et des granulations des mastocytes du côlon

Résumé Les auteurs ont étudié la biréfringence du mucus du côlon chez le rat, le cobaye et le lapin, au moyen des colorations métachromatiques au bleu de toluidine et aux acridines. Ils démontrent une biréfringence positive du mucus extracellulaire. Les granulations des mastocytes, dans le même matériel, sont anisotropes. L'anisotropie du mucus et des granulations des mastocytes est présente après fixation-coloration simultanée au bleu Alcian et au vert Alcian. La biréfringence du mucus extracellulaire reste également positive avec les phtalocyanines. En microscopie électronique, les auteurs démontrent, à l'aide du bleu Alcian, une structure filamenteuse parallèle du mucus s'échappant de la cellule. Un aspect hétérogène des granulations des mastocytes est aussi mis en évidence par cette méthode. Ils discutent l'aspect de la réaction métachromatique en fonction de l'anisotropie d'une structure.

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Ultrastructure of mucus in goblet cells and of granules of mastocytes in colonAnisotropy, metachromasia and electron microscopy

Summary The authors have investigated the birefringence of the colic mucus in the guinea pig, the rat and the rabbit before and after of metachromatical staining with toluidine blue and with acridines. They demonstrate a positive birefringence of the extracellular mucus. The granulations of the mast cells in the same animals are anisotropic. The anisotropy can be seen in the mucus and in the granulations of the mast cells after a combined fixation and staining with a mixture of glutaraldehyde and Alcian blue or Alcian green. The birefringence of the extracellular mucus also remains positive with these phtalocyanin dyes. Using the electron microscope, the authors demonstrate, by means of Alcian blue, a filamentous structure with a parallel orientation in the mucus while it flows out of the cells. The same method allows the vizualisation of a heterogenous aspect in the granulations of the mast cells. They discuss the theoretical aspects of the metachromatical reaction in relation with the anisotropy of a structure.

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Nous remercions vivement le Prof. G. Romhányi de l'Université de Pecs (Hongrie) d'avoir bien voulu examiner nos préparations et de nous avoir conseillé dans l'élaboration de ce travail.Nous remercions sincèrement le Dr. J. E. Scott du Canadian Red Cross Memorial Hospital, Taplow, Maidenhead, Berks (Angleterre) d'avoir examiné nos courbes spectrophotométriques du bleu Alcian-héparine et de nous avoir donné son avis.Ce travail a été partiellement réalisé grâce au crédit no 3. 141. 69 du Fonds National Suisse pour le Développement de la Recherche Scientifique.     

Structure du noyau des Blastodinium (Dinoflagellés parasites)

Résumé Les observations photoniques et ultramicroscopiques concernant les Blastodinium, parasites de Copépodes, étudiés à tous les stades de leur développement intra-intestinal nous ont apporté les résultats suivants:Le Trophocyte subit de profondes transformations nucléaires avant de commencer à se diviser (éndettement nucléolaire et passage des grains ribonucléoprotéiques dans le cytoplasme); les sphères archoplasmiques liées aux noyaux se divisent avant eux et apportent leur contribution dans les synthèses membranaires; la division nucléaire est une pleuromitose simple, sans cinétochores et sans centrioles: on peut observer tous les stades définis de, la mitose, exceptée l'interphase; la métaphase est très difficile à saisir, surtout dans les espèces à mitoses accélérées. Les faisceaux de microtubules contenus dans les plasmodendrites qui perforent les noyaux toujours en mitoses au cours de la sporogenèse, ne sont jamais en contact avec les chromosomes; nous avons entrevu leur rôle dans la cyclose hyaloplasmique. Durant les phénomènes sporogenétiques, un cycle régulier de condensation chromosomique s'effectue, sans perte de DNA. Dans les stades peu condensés, l'arrangement fibrillaire des chromosomes est inorganisé, puis ceux-ci montrent un agencement en séries d'arceaux réguliers qui disparaît dans les stades les plus condensés.L'enveloppe nucléaire joue un rôle prépondérant dans la traction, l'orientation et la ségrégation du matériel chromosomique. Nous avons recherché également une série d'explications concernant le déterminisme des phénomènes de condensation chromatique.Dans cet exemple précis, noyaux et phénomènes mitotiques démontrent parfaitement cette situation intermédiaire des Dinoflagellés, entre Bactéries et Eucaryotes.

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Nuclear structures of Blastodinium Chatton (parasitic dinoflagellates)Division and chromatic Condensation

The mitotic mechanism in Blastodinium Chatton has been studied by photonic and electronic microscopy. Divisions of the archoplasmic spheres precede that of the nuclei and their movements are interconnected. Stages of mitosis follow one another without interphase; they are telescoped, which makes the study of the chromosome cycle more difficult. Progressive condensation of nuclei and chromosomes takes place in the various sporogenetic layers within the same parasite. Cytophotometric measurements show that there is no loss of DNA during successive mitosis. The nuclear envelope plays an important part in the traction, orientation and segregation of the chromosomes. The cytoplasmic invagination which perforate the nuclei contain considerable masses of microtubules whose role in the activation of the hyaloplasmic cyclosis and membranous synthesis is suggested.—In longitudinal section, the chromosomes show a fibrillar arrangement in regular arches in the non-condensed stages and irregular arches in more condensed stages, with a lesser diameter.—The type of nuclear division is a very simple pleuromitosis without kinetochores and centrioles; the role of the nuclear envelope in the chromosomal mechanism appears to be preponderant.

     

Création du genre Californiella N.gen. (Rhodophycophyta) et révision du genre DasyporellaStolley, 1893 (Dasycladales)

The genus Dasyporella was created by Stolley in 1893. Later, two different species were assigned to this genus under the same specific name Dasyporella norvegica. One of them was misinterpreted by Johnson & Konishi (1959) which introduced a confusion in the genus definition. The revision of the genus Dasyporella was therefore necessary and the study of new specimens belonging to the misinterpreted species have led to the creation of a new genus: Californiella. This new genus clarifies the concept of Dasyporella with the reinstatement of its original definition.     

Contribution à l'étude du genre Cytophaga (Winogradsky)

Sans résumé     

Apports de la palynologie a la connaissance du Pliocène du Roussillon (sud de la France)

The present study illustrates clearly how pollen analysis may be applied to stratigraphy from a botanical point of view. Within a chronologically reliable frame (Middle Pliocene for the marine deposits on the basis of Foraminifera record; two subzones for continental deposits on the basis of Mammals record: Hautimagne for Terrats fauna, Sète for Serrat-d'en-Vacquer fauna), palynology provides a good stratigraphical boundary: the extinction of the Taxodiaceae. In a remblayage area, it is established that a continental level is not necessarily younger than a marine one unless they are superposed. Many profiles are replaced according to the «progradation of the pliocene gulf of Roussillon. The boundary between marine and continental deposits cuts through the chronological line of the Taxodiaceae extinction. The flora investigated (93 taxa) is the first known for the Pliocene of this area. The extinction of the Taxodiaceae in southern France has a climatic cause: the setting in of a mediterranean rhythm (dry summers). This extinction is much older than the one which took place in Italy (Tiberian boundary) and in the Netherlands (Reuverian-Pretiglian boundary).     

Premières données sur les Ostracodes du Cénomanien deYougoslavie (istrie du sud)

enAn Upper Cenomanian Ostracode assemblage has been identified near Premantura, South Istria (Yougoslavia), in an internal carbonate platform deposit. This appears of peculiar interest because of lack of datas concerning this area during the Cretaceous. Systematical studies are proposed and two new species erected: Rehacythereis apulicus nov.sp and Perissocytheridea istriana nov.sp. Some attempts are given upon paleoenvironments and paleobiogeographical signification.     

Innervation du muscle rétracteur antérieur du byssus (ABRM) de Mytilus edulis L.

Summary Detection of nerve structures containing 5-HT were described in the anterior byssus retractor muscle (ABRM) in Mytilus edulis L. after using the fluorescence microscope technique of Falck. We are able to confirm our previous results and assumptions given by histology and electron microscope studies: the neuromuscular en passage junctions, largely distributed within the ABRM, contain 5-HT.     

Révision du genreProstrepsiceros Major 1891 (Mammalia,Bovidae)

The study of new fossils from the Miocene of Macedonia (Greece) has led us to a revision of the genusProstrepsiceros, which we propose to divide into two subgenera:P. (Prostrepsiceros) andP. (Helicotragus), these subgenera comprising respectively two and three species.     

L'organe de Bellonci du Crustacé Isopode Sphaeroma serratum (Fabricius)

Summary The organ of Bellonci in Sphaeroma serratum comprises principal cells which consists of a cell body and an outer segment connected by a ciliary piece. The outer segment is prolonged by bundles of very long microvilli which are free in the central lumen, whereas the cell body is bounded by flat bordering cells. In the cell body there are large electron-dense spheres and a lot of granules, the latter appearing to be glycogen according to results obtained with light and electron microscopical cytochemical methods. These substances are released in the central lumen. The principal cells have not the fine structure of neurosecretory but of sensory cells. They may be photosensitive or chemosensitive elements. These results set the problem of the homology of the organs named of Bellonci seen in various groups of Crustacea.

Equipe de recherche associée C.N.R.S. n 230: Physiologie et Génétique des Crustacés.     

Les faunes d'ammonites du Carixien inférieur et moyen du gisement des Cottards (Cher)

The study of the traditional Cottard layer forthe first time allows the exact succession of lower and middle Carixian ammonites to be established.The most striking fact is the evolution of the Tropidoceras-Acanthopleuroceras lineage, a regular modification of the ribbing density and L¹ structure, an iterative variation of section and tuberculization.Precisions are given on Polymorphites and Beaniceras and three new species are described: Polymorphites evolutus, Beaniceras cottardiense, Acanthopleuroceras alisiense.     

L'ultrastructure du testicule de lézard vivipare (Reptile,Lacertilien)

Résumé Les cellules de Sertoli du testicule de Lacerta vivipara ont été étudiées en microscopie électronique chez des animaux récoltés entre le printemps et l'automne pendant deux années et chez des animaux hypophysectomisés en automne.Ces cellules contiennent de nombreuses mitochondries de petite taille à crêtes lamellaires, des ribosomes libres, un reticulum endoplasmique lisse moyennement développé, plusieurs petits dictyosomes formant l'appareil de Golgi, des liposomes et des microtubules. Elles renferment aussi de nombreux corps denses de grande taille qui paraissent être de nature lysosomiale. Le glycogène a été particulièrement étudié. Il est formé de particules dispersées au hasard dans le hyaloplasme. Des variations saisonnières dans la teneur en glycogène ont été notées. Chez les hypophysectomisés, les cellules de Sertoli contiennent de grandes quantités de ce métabolite dont les particules sont concentrées dans des petites plages, souvent autour des liposomes.Les rôles possibles des cellules de Sertoli sont discutés: soutien et apport de nourriture aux cellules germinales, production d'hormones et phagocytose des corps résiduels. Les variations de la teneur en glycogène sont également discutées.

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The fine structure of the lizard testisII. The Sertoli cells. Study of the glycogen

Summary Sertoli cells of the testis of Lacerta vivipara have been studied electron microscopically in animals obtained between spring and autumn during two years and in animals hypophysectomized in autumn.These cells contain numerous small mitochondria with lamellar cristae, free ribosomes, smooth endoplasmic reticulum moderately developed, several small dictyosomes forming the Golgi complex, lipid droplets and microtubules. There are numerous dense bodies of large size with an heterogeneous content which seem to be of lysosomial nature. Glycogen consists of particles dispersed at random in the hyaloplasm. Seasonal variations in the content of glycogen are noted. In hypophysectomized animals Sertoli cells contain large amounts of that metabolite whose particles are concentrated in small areas often around the lipid droplets.Possible role of the Sertoli cells concerning mechanical support and nutrition of the germinal cells, production of hormones and phagocytosis of residual bodies are discussed. The variations in the glycogen content are also discussed.