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The vertical distribution of Albian ammonites of the North Pacific Province is described on the basis of several sections located in Northern California. Nine Albian ammonite assemblages are identified, compared to the 4 previously described by Murphy in 1956. Owing to several gaps of observation possibly more assemblages could exist. In the North California Albian history, the first results show a succession of confinement periods - with numerous endemic faunas - followed by periods of open communications with other faunal provinces. As an example, the base of the Middle Albian is marked by exotic ammonites coming from the Tethyan realm (Oxytropidoceras, Lyelliceras) and from the Arctic Province of the Boreal realm (Gastroplites, Pseudopulchellia). These ammonites - except Oxytropidoceras - were not known in that area and are described relatively to their palaeobiogeographical interest. Although rare these migrant faunas give valuable elements to correlate these various provinces. Planktonic foraminifera confirm the existence of open sea communications during the uppermost Albian.With such faunal links, a comparison is proposed between the Albian ammonite zonation of Northern California and the standard and phyletic ones of Europe. This attempt suggests that the major connections between the three faunal provinces are established at second order peak transgressions in the Early and Middle Albian, and during the sea-level high of the Late Albian transgressive period. So, it seems that the vertical distribution of Albian non-endemic ammonites of North California and Europe is largely controlled by global eustatic events. Two palaeobiogeographic maps for Early and Middle Albian and one map for the late Late Albian show the migration outer of these exotic ammonites.  相似文献   

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Some animal and mineral resources, rarely identified in the levels of the Cantabrian Magdalenian, were exploited by the Paleolithic populations of the Nalón Valley (western Asturias) at the end of the Pleistocene. In this research, we present some of them, preserved in the Las Caldas Cave: dental remains and representations of marine mammals, marine crustaceans and molluscs, and diverse remains of amber and jet. These were selected, collected in ecosystems far away from the cave and, finally, transformed by the groups. These remains seem to complement the common resources exploited in Magdalenian paleoeconomy (e.g., ungulates, birds, fish, small carnivores, vegetables, flint, quartzite, quartz) recovered and exploited biotopes closest to the site. Our aim is thus to confirm a certain mobility of these communities towards the specific sources of raw material in search of subsistence resources potentially used in the activities of these communities (e.g., food, technology, social and symbolic expression, exchange).  相似文献   

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G. Iperti 《BioControl》1964,9(2):153-180
Sans résumé I.N.R.A. — Station de Zoologie agricole et de Lutte biologique d'Antibes.  相似文献   

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New investigations of the nuclear cycle in the gymnostome ciliate Loxodes rostrum verify the long-neglected hypothesis proposed by Bütschli that in this multinucleated ciliate the macronuclei never divide. The consequences of this "caryosterose" are compensated for by a process of endomixis, that is, by the transformation of a certain number of the micronuclei, during vegetative multiplication, into new macronuclei.
The nuclear cycle in the gymnostome Centrophorella fistulosa does not show any aspect of nuclear division. Interpretation of this supposes the existence of polyenergid nuclei which fragment, during the interdivisional period, into subnuclei; among these some evolve in the somatic and macronuclear direction, before disappearance by karyolysis; others, corresponding to the micronuclei, grow by endomitosis, and reconstitute the polyploid and polyenergid nuclei. Thus the very particular nuclear cycle of C. fistulosa is believed to exhibit a new aspect in the endomictic process of nuclear reorganization.  相似文献   

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An examination of lithic industries evolution during VI millenium cal BC shows us transformations of mesolithic technical systems under neolithic pressures, with regional variations. Contrasting classical views, mesolithic groups seems to be less active on atlantic façade than similar groups of France or Spain. This technology transfers are not peripheral phenomenons but testify to intense interactions between mesolithic and neolithic communities, especially on weapons.  相似文献   

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Phagocytose et pinocytose chez les Spongillidae   总被引:2,自引:0,他引:2  
Résumé Un ensemble de techniques récentes basées sur l'emploi d'un colorant fluorescent en lumière ultra-violette, FITC, a été adapté à l'étude in vivo de la nutrition chez les Spongillides.L'emploi d'Escherichia coli marquées au FITC a permis d'établir que chez Ephydatia fluviatilis et Ephydatia mülleri, la nutrition par les bactéries comporte une série d'étapes en accord avec le schéma proposé par les auteurs qui ont étudié l'ingestion de particules non nutritives comme du carmin et de l'encre de Chine: Les bactéries sont principalement captées au niveau des choanocytes (Fig. 1 à 6). Elles sont ensuite transmises aux archaeocytes, aux collencytes et aux cellules amoeboïdes du mésohyle (Fig. 4 à 10).Dans les cellules du mésohyle, principalement au niveau des archaeocytes, les bactéries ingérées perdent leur morphologie propre (Fig. 6, 11 à 14). Ceci constitue un argument de plus en faveur de l'hypothèse selon laquelle la digestion s'effectue principalement au niveau des archaeocytes. En fin de cycle, certains archaeocytes concentrent les déchets fluorescents qui sont ensuite expulsés dans le système exhalant (Fig. 11, 12).En outre, à l'aide de caséine et de sérum de lapin couplés au FITC, il a été possible de montrer que Ephydatia fluviatilis et Ephydatia mülhri prélèvent des protéines en solution dans le milieu. Elles le font à l'aide des mêmes types cellulaires que ceux qu'elles utilisent pour se nourrir de bactéries: Les protéines fluorescentes sont concentrées par les choanocytes (Fig. 15, 16, 21, 22) puis transmises aux archaeocytes et aux cellules amoeboïdes du mésohyle (Fig. 15 à 20, 25, 26). Les pinacocytes et les spiculoblastes peuvent également concentrer de la caséine marquée, mais dans une moindre mesure (Fig. 23, 24, 29). L'accumulation des déchets suivie de leur expulsion dans le milieu ambiant se fait comme dans le cas des bactéries au niveau des canaux exhalants (Fig. 27, 28).D'autre part, le fait que chez Ephydatia fluviatilis nous n'ayons pas pu mettre en évidence d'activité protéolytique extra-cellulaire, renforce l'idée que la digestion est strictement intra-cellulaire chez les Eponges.
Phagocytosis and pinocytosis in spongillidsAn in vivo Study of the ingestion of bacteria and proteins labelled with an u. v. fluorescent dye
Summary Several recent techniques using the ultra-violet fluorescent dye FITC, were adapted for the in vivo study of Spongillid nutrition.Studies of the ingestion of FITC-lahelled bacteria by Ephydatia fluviatilis (L.) and Ephydatia mülleri (Lieberkühn) show that the series of steps involved are the same as those proposed by others in their studies of the ingestion by Spongillidae of non-nutritive particles such as carmine and Indian ink: Most of the bacteria are ingested by the choanocytes (Figs. 1–6). They are further transmitted to the archaeocytes, collencytes and amoeboid cells of the mesohyle (Figs. 4–10).In the cells of the mesohyle, principally in the archaeocytes, the bacteria lose their characteristic morphological appearance (Figs. 6, 11–14). This fact supports the hypothesis that the archaeocytes are the main organ for digestion in Spongillidae.Fluorescent wastes are accumulated and rejected in the exhalant channels by some archaeocytes (Figs. 11, 12).Experiments using FITC-labelled casein and rabbit serum proteins demonstrate, in addition, that E. fluviatilis and E. mülleri remove soluble proteins from the surrounding medium. We have further shown that this usually involves the same cell types as those used for ingestion of bacteria: Labelled proteins are concentrated by the choanocytes (Figs. 15, 16, 21, 22); then distributed to the archaeocytes and the amoeboid cells in the mesohyle (Figs. 15–20, 25, 26).There is evidence that pinacocytes and spiculoblasts are also able to concentrate labelled casein, though in a smaller quantity (Figs. 23, 24, 29). Fluorescent wastes are excreted in the surrounding medium through the exhalent channels, after having been concentrated by archaeocytes (Figs. 27, 28).The fact that we were unable to demonstrate the existence of an extracellular proteolytic activity for E. fluviatilis, supports the conclusion that digestion by sponges is strictly intracellular.


Je tiens à exprimer mes remerciements au Professeur Rasmont pour ses conseils et l'aide qu'il m'a prodiguée tout au long de ce premier travail.  相似文献   

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SYNOPSIS. The taxonomic position of Selenidiidae Brasil in the class of gregarines is discussed in relation to the study of its life cycles, its possible schizogony and the fine structure of its trophozoites. The cycle of gregarines which belong to the genus Selenidium Giard is characterized by trophozoites with pendular or coiling movements, nuclear transformations in gamonts during syzygy just before cyst formation, anisogamy, sporocysts with 4 sporozoites. Schizogony of the Selenidiidae is not yet demonstrated. The “kystes á meérozoites” within the gut epithelium of Sabellaria alveolata, could be one of the stages of schizogony of S. hollandei. This sole example in our study and the absence of schizogony in numerous species, especially in S. pendula, the type species, shows that this criterion is uncertain, actually, in the definition of the order Archigregarinida Grassé. Ultrastructural studies of S. hollandei and S. pendula show that the cortical region in trophozoites of the genus Selenidium is different from that of Eugregarinida. In the Selenidiidae the epicyte is composed of longitudinal folds. Under the wall, consisting of 3 membranes there is a well-defined pellicular fibrillar system. In S. hollandei, the trophozoite has a fibrillar formation, corresponding to a conoid in its anterior region. The trophozoites of S. hollandei and S. pendula contain anterior dense bodies or rhoptries which are very well developed. All these characteristics conform to the ultrastructural organization of the dissemination forms (merozoites, schizozoites, sporozoites): The results allow one to give a new definition of the Order Archigregarinida: Order Archigregarinida (Grassé): Gregarines with ultrastructural organization of the trophozoites similar to that of dissemination forms. Presence of a well defined pellicular fibrillar system. Intestinal parasites of polychaete worms.  相似文献   

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Cephalopods and conodonts from the upper part of the Aspe-Brousset Limestones and lower part of the Iraty Limestones in Central and Western Pyrenees are described. Two levels differing in age are distinguished on their behalf. The oldest one belonging to the Late Visean or Early Serpukhovian yields specimens described as Goniatites baylei Leymerie, 1957, by Mirouse (1957, 1962). They are placed here in the species Dombarites falcatoides Ruzhentsev and Bogoslovkaya, 1971 for which the new subspecies D. falcatoides mirousei is established. The upper level corresponds to the Albergian (upper Serpukhovian) and is characterized by Proshumardites delepinei Schindewolf, 1939. Numerous conodonts belonging to the Lochriea and the Gnathodus groups occur together with this fauna. The joint study of goniatites and conodonts allows us to show the relationship existing between the distributions of both these two groups of organisms as well as to provide precisions on the stratigraphic and the palaeogeographical data in these areas.  相似文献   

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