Chitinozoaires ashgilliens de l'Anti-Atlas (Maroc)

Thirty three species of Chitinozoans are recorded inthe Upper Ktaoua and in the Lower Deuxième Bani Formations (Anti-Atlas, Morocco). These two lithological units have been refered to the upper part of the Ashgill Series on Trilobite, Brachiopod and Echinoderm evidence. This age assignment is well supported by the present study of the Chitinozoans. Strong affinities with North american Chitinozoan assemblages (Anticosti Island, Québec; Oklahoma, U.S.A.) are pointed out. The Upper Ktaoua Formation can be correlated with part of the Vaureal Formation (Richmodian of Quebec); the Lower Deuxième Bani Formation seems to be of the same age as the lower part of the Ellis-Bay Formation (Gamachian of Quebec).     

Decouverte de Planomalina buxtorfi (gandolfi) et d'autres foraminiferes plancotoniques inattendus dans l'albien superieur d'abbotscliff (kent,angleterre); consequences paleogeographiques et biostratigraphiques

The discovery of Planomalina buxtorfi (GANDOLFI) in the Upper Albian (Stoliczkaia dispar zone) of Abbotscliff (Kent, England), associated with Rotalipora appenninica (RENZ), Praeglobotruncana delrioensis (PLUMMER), Hedbergella simplex (MORROW) and Hedbergella costellata SAINT MARC, appreciably modifies data on the geography and stratigraphical distribution of these species in the boreal realm.     

Polymorphime de l'oleate de sodium anhydre

By careful experiments with a DTA apparatus equipped with a closed sample-holder for operations at elevated temperatures and pressures, it was found that pure sodium oleate shows 8 phases: I crystalline, II and III not well defined, IV and V face centered structures, VI ribbons phase, VII and VIII labile lamellar structures. These results are discussed and compared with the other literature data.     

Sur quelques echinodermes(Cystoides et Crinoides) de l'Ashgill d'Aragon (Espagne)

The material collected in the outcrops of Fombuenaand Luesma allows to specify the distinctive characters of the genera Corylocrinus and Caryocrinites, to describe two new species and to complete the morphology of Heliocrinites rouvillei and Proteocystites hispanica. The Crinoid association of these localities shows a very close composition with that of Coat-Carrec (Finistère). The new observations establish definitively the structure of the dorsal cup and the oral face of Mespilocystites. The occurence of the genera Stichocystis, Eucystis and Mespilocystites is recorded for the first time in Aragon. Cystoids and Crinoids confirm the existence of Ashgillian in the western part of the Armorican Massive.     

Tetravaccinites collignoni N. Gen., N. Sp. et les autres rudistes du santonien superieur de l'aude (France)

The three principal levels of rudists of the “Montagne des Cornes” are of upper Santonian stage. Their rudist's associations are characteristic. Tetravaccinites collignoni n. gen., n. sp. found in the upper level is described.     

Etude de l'activite de l'arginine decarboxylase dans les jeunes plantes de Glycine max privees de leurs cotyledons

l-Arginine carboxy-lyase and l-ornithine carboxy-lyase activities were investigated in young decotylized Glycine max plants growing in the light on a liquid medium in the presence of ammonium chloride or nitrate. Only the first enzyme could be detected. It had pH optimum at 7.0 activity and there is much more activity in plants cultivated on ammonium chloride than in plants grown on nitrate.     

Action de l'hormone juvenile et de certains mimetiques sur l'epithelium intestinal chez Galleria mellonella

We have investigated the influence of juvenile hormone (JH) on the intestinal epithelium of G. mellonella, in vivo and in vitro. The larvae undergoing a supernumerary instar present a typical larval epithelium with columnar (CL) and globlet (CF) cells; the spinning period is characterized by a delay and a loss of synchronism in the process of differentiation of intermediates cells (Ci) typical of the pharate pupa. The larval-pupal intermediates show true mosaïcs in which Ci and CF are juxtaposed; however, the ratio of Ci in the epithelium progressively increases.The injection of JH at the beginning of spinning induces the appearance of CF just as Ci should normally grow. Hormone administration during the second half of the spinning period modifies the differentiation of epithelial cells: they become taller. We consider them to be cells engaged in pharate pupal differentiation, and which have then been partially oriented toward larval differentiation.These results show that the intestinal epithelium is a competent tissue, the sensibility of which to JH, is higher than that of the epidermis. The basal cell plasticity is very important and the action of JH on their differentiation may lead to CL or CF, to tall cells, and to Ci, depending on hormonal rate. In vitro, the experiments show that the action of JH is probably direct on the target tissue. The fact that JH can act very late as a modifier of the differentiation of the growing epithelial cells exclude the possibility that the hormone exercises its control through DNA replication.     

Mise en evidence de l'existence de sensilles chemorecepteurs sur les antennes d'un crustace mysidace cavernicole et de l'intervention de ces sensilles dans la detection d'un extrait de nourriture

The cavernicolous crustacean Antromysis juberthiei showed unexpected behavior when presented with food extract : it avoids the area of odor inflow. This avoidance reaction is reduced by removal of various combinations of antennae and disappears almost with bilateral removal of the first antennae (the aesthetasc-bearing antennules).     

Tetrapleuroxylon limagnense n. sp., bois fossile de l'allier (France)

Found in a Pliocene terrace near Vichy (department of Allier), the fossil wood studied here shows affinities with some recent tropical Leguminosae. In the Massif Central, tropical Leguminosae are known mainly from earlier times (Eocene to Miocene). This may suggest the redeposition of the warm-climate wood in a fluvial sediment of a more recent and colder period.     

Palynoflores dans la coupe de l'Albien de Foz do Folcao (Portugal)

In the area of Lisbon (Portugal) near Foz do Folcao and along the sea-shore, the transgressive facies of the marly 0611 Albian may be seen sesting on the “Upper continental sandstones of Almargem”. On the basis of the variety and of the relative frequencies of reticulate pollen grains in particular, the following age assessment can be made. The topmost part of the “Upper sandstones of Almargem” as well as the lowermost transgressive facies, just underlaying the albian levels with associated faunas, are suggested to be middle Albian.     

Incorporation de phenylalanine,de glucose et d'acide cinnamique dans les flavonols de l'oignon

In Allium cepa bulb scales, incorporation of ¹⁴C-phenylalanine, cinnamic acid and glucose were studied in relation to flavonol synthesis. The best incorporation into flavonols is obtained with either cinnamic acid or phenylalanine. ¹⁴C-glucose gives a slow incorporation into flavonol aglycone; this is because there is a big pool of free glucose in the scales in which the precursor is diluted. Under certain conditions, free cinnamic acid is quickly incorporated in a complex which may be a glycoside. After short labelling experiments with phenylalanine or cinnamic acid, some free precursor can be found in the scales a few days later but it is not available for flavonol synthesis. In these conditions, flavonol analysis shows in some cases, no turnover and in others, a turnover of 10% per day due to catabolism.     

L'ancistrocladonine et L'ancistroealaensine deux alcaloides nouveaux isoles de L'Ancistrocladus ealaensis

Ancistrocladonine and Ancistroealaensine are two new alcaloids isolated from the roots of Ancistrociadus ealaensis. In their UV spectrum they show strong resemblance to 1,8-dimethoxy naphthalene. Their structures were determined on the basis of spectral data of the bases and their Hofmann degradation products.     

Les sterols de l'Ascomycete Leptosphaeria typhae

A mixture of C₂₈ and C₂₉ sterols have been isolated from Leptosphaeria typhae grown in vitro on “oat water” and characterized by GLC and MS. Mono-, di- and tri-unsaturated sterols are present in the extracts of fungi cultivated both in the dark and in the light but the sterol composition is different. The influence of “oat water” on sterol structure has been determined by comparison with the sterols of the same fungus grown on synthetic medium in the dark.