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1.
Pachnobium dreuxi, nouvelle espèce et nouveau genre de Curculionidae Ectemnorrhininae des îles Crozet, dans l’Océan Indien sud, a été découvert sous forme fossile dans une séquence sédimentaire holocène. Deux spécimens modernes ont ensuite été trouvés parmi le matériel conservé au Muséum national d’Histoire naturelle de Paris. Il diffère très nettement de toutes les autres espèces connues de la sous-famille par son rostre profondément émarginé au sommet, sa tête massive, sa sclérotinisation réduite, ses tibias antérieurs droits et aplatis, etc. Sa biologie et son écologie sont presque entièrement inconnues, bien que certains aspects de sa morphologie comme sa faible sclérotinisation et ses yeux relativement petits soient en faveur d’une vie cachée, voire hypogée, par exemple dans la litière végétale ou dans les nids de pétrels. Les reconstructions paléoenvironnementales suggèrent qu’il fréquente des habitats à végétation dense. L’absence de captures modernes à l’île de la Possession pose la question de sa présence actuelle dans cette localité.  相似文献   

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Summary Four new species of hystrignathid nematodes are described from the midgut caeca of Passalus unicornus (Coleoptera: Passalidae) from St. Lucia, West Indies. Artigasia horridospina n.sp. is differentiated from A. dispar van Waerebeke, 1973 by virtue of fewer rows of spines in the oesophageal region and in possessing lateral alae, and from A. insignia Travassos & Kloss, 1958 in the extent of the oesophageal spiens and in having the lateral alae commence more anteriorly. The first annule is also much shallower than that of A. insignia. Longior semialata n.sp. is differentiated from L. longicollis Travassos & Kloss, 1958 on body length, b ratio, egg size and the starting point of the lateral alae. Mentecle magnifica n.sp. differs from M. parvus Travassos & Kloss, 1958 in having the spines of the oesophageal region extending much further down the body and in having ridged eggs. It is also longer and relatively thinner. Paraxyo ensicrinatus n.sp. differs from P. monodelpho Travassos & Kloss, 1958 in having a proportionately longer tail. The spines in the oesophageal region also extend considerably further posteriorly than in P. monodelpho.Two types of male associated with the above nematodes are described and illustrated, but not assigned to females. Pulchrocephala? pulchrocephala Travassos, 1925 is redescribed from the gut of the mole-cricket Scapteriscus vicinus.Scanning electron micrographs of four of the described species are given and briefly discussed. ac]19801024  相似文献   

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Bartolius pierrei n. g., n. sp. (Digenea: Gymnophallidae) is described from metacercariae and naturally and cultivated obtained adults from southern Argentina. The second intermediate host is Darina solenoides (King) (Bivalvia: Mactridae) and the definitive host is Larus dominicanus Lichtenstein (Aves: Laridae). The diagnostic characters are as follows: Body small, oval. Oral sucker without lateral projections, twice size of ventral sucker (except in young metacercariae). Caeca short (in adults), without dorsal diverticula. Ventral sucker in posterior third of body. Ventral pit absent. Seminal vesicle bipartite. Ovary post-testicular. Vitelline glands paired, compact, close to ventral sucker. Uterus in fore- and hindbody. Genital atrium tubular. Genital pore inconspicuous, close to anterior margin of ventral sucker. Excretory vesicle Y-shaped with very short stem. Excretory formula: 2[(2+2)+(2+2)]=16. Bartolius is distinguished from other genera of the Gymnophallidae by the post-testicular position of the ovary.  相似文献   

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From the Buschmann-Klippe-Formation, mainly considered as Late Precambrian in age until now, the ArchaeocyathaBuschmannia roeringi, n. gen., n. sp. is described. Based on this discovery, an Early Cambrian age for the Nama-group is assumed.  相似文献   

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Summary The cytology of two species of Luffia has been studied. The first one, L. lapidella, is bisexual, the second one, L. ferchaultella, parthenogenetic and derived from the first. In both species the females have a diploid number of 61 chromosomes. The male of lapidella has 62 chromosomes.The development of the fertilized egg of L. lapidella does not show any noticeable peculiarity other than the slow rate of the first meiotic division.The meiotic divisions of the parthenogenetic egg of L. ferchaultella begin normally as in lapidella but are interrupted either at the end of anaphase I or at metaphase II or anywhere between these two stages. Through various procedures the two haploid plates reunite to form a new metaphase spindle, which carries out a normal though diploid second meiotic division. The restoration of the diploid number happens therefore by means of the fusion of the first polar body with the nucleus of the oocyte II. The different procedures which lead to it have been studied and their variability examined in connection with the environment, the morphological types of the females and the geographical distribution of the species.
Cytologie Comparée de l'espèce Parthénogénétique Luffia ferchaultella Steph. et de L'espèce bisexuée L. Lapidella goeze (Lepidoptera, Psychidae)


Travail subventionné par le Fonds National Suisse de la Recherche Scientifique.  相似文献   

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In this article, the paraplegics’ possibilities for procreation will be examined. A first chapter will deal with the testicle functioning along with the study of hormonal measuring and testicle histology (study involving 100 patients). As a result, it appears that, after a testicle biopsy, there is a testicle lesion of neurological origin that is sometimes irreversible. On the contrary, the endocrinal testicle lesions have proved reversible under stimulation or spontaneously. A second chapter will deal with the different techniques to obtain an ejaculation and the semen analysis. The techniques that were used being: massage by vibrator, electroejaculation, ejaculation through pharmacological stimulation. The study focuses on 124 ejaculatory tests among which 64 forward ejaculations (52%) and 4 bachward ejaculations (3%) were obtained. The resulting semen analysis revealed a spermatozoon count greater than 20 millions per millilitre (that is 51,5%) and smaller than 5 millions in 11 cases (16%).  相似文献   

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Stress, which originates in the brain, can influence spermatogenesis hormonally or via the nervous system. The hormonal route commences with the central secretion of Corticotrophin-Releasing Factor, leading to a fall in LHRH production, a decrease in Leydig cell LH receptors and a decrease in 17 a hydroxylase activity. Thus, in the case of major, prolonged stress, testosterone secretion falls, which in turn affects spermatogenesis. However, given that the testosterone threshold required for normal seminiferous epithelium function is significantly less than the mean circulating level of this hormone, the importance of low intensity stress remains unknown. The nervous route involves catecholaminergic fibres which, in the testis, innervate the Highmore corpus, the vessels, the area adjacent to the Leydig cells, and the basement membrane of seminiferous tubules. The experimental destruction of these fibres leads a regression of the seminiferous epithelium. Moreover, the experimental ablation of the rat anterior neocortex leads to changes in spermatogenesis. Therefore, given that the endocrine system does not seem to be involved in these changes, these results indicate that the highest level of the nervous system may participate in the controlling the germinal epithelium which, all things considered, would tend to support psychosomatic influences. However, given that the number of spermatozoa varies significantly between ejaculate and independantly of the level of testosterone secretion necessary for normal spermatogenesis, it may be hypothesized that it is only when sperm production is low that temporary stress, in aggravating the situation, becomes deleterious to spermatogenesis. Since, under normal conditions, such periods are short, the role of the influence of stress on spermatogenesis can only be relative. Nevertheless, if variations occur during permanently low sperm production, the likelihood of negative effects is increased. Consequently, the impact of stress or psychological factors on spermatogenesis might well depend upon particular circumstances.  相似文献   

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More than 90 remains of rhinoceroses bones and teeth have been recovered from the Layna Pliocene deposit. They correspond to a middle sized animal with stout bones and is quite different from both the large sized Pliocène D. megarhinus, the lower Villafranchian D. jeanvireti and the slim small Villafranchian D. etruscus. Its a new species belonging to the Dicerorhinus genus: D. miguelcrusafonti nov. sp. This species is also found in the Perpignan Pliocene formation, together with D. megarhinus.  相似文献   

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《Comptes Rendus Palevol》2005,4(3):225-234
Ancylotherium cheboitense nov. sp., new Chalicotheriidae (Mammalia, Perissodactyla) from the Late Miocene of the Tugen Hills (Kenya). Seven articulated bones of a left foot, comprising the talus, incomplete calcaneum, cuboid, co-ossified navicular + ectocuneiform, the mesocuneiform, metatarsals II, III and IV, as well as an isolated lower molar, were discovered at Cheboit, Baringo District, Kenya. All these remains came from the Kapgoywa Member (5.9 to 6.1 Ma) at the base of the Lukeino Formation. They belong to a new species of Ancylotherium, A. cheboitense nov. sp. This Schizotheriinae is characterised by its remarkably stocky skeleton, its high and wide talus, its massive metatarsals, in particular the fourth, of which the anterior surface of the diaphysis is strongly depressed. A. cheboitense is smaller but much more massive than Ancylotherium hennigi and even more so than Chemositia tugenensis, both species that have (at least partly) about the same age. It could represent an attempt to adapt to a humid habitat. To cite this article: C. Guérin, C. R. Palevol 4 (2005).  相似文献   

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The authors describe and illustrate two trematodes from Belize (Central America): Paramaritremopsis solielangi n. sp. from the small intestine of Arenaria interpres is characterised by a body length of 478 m, two short and pre-acetabular caeca, part of the uterus in close association with the cirrus-sac and left caecum, vitelline glands in the shape of a horseshoe, a short pre-ovarian cirrus-sac containing a long, cylindrical, voluminous and unarmed cirrus (size when evaginated: 150×20–30 m) and Microphallus kinsellai n. sp. from the caeca of Actitis macularia characterised by a body length of 370 m and a phallus which is 30 m in diameter and asymmetrical (basically a pad with a moderately developed accessory lobe) and a straight ejaculatory canal. Levinseniella carteretensis is another microphallid recovered from Arenaria interpres. The term of ``phallus' is proposed to name the male copulatory organ which characterizes the Microphallinae.  相似文献   

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Résumé 1) Une espèce nouvelle dePenicillium, P. marneffei,Segretain, Capponi, Sureau, a été isolée d'un rongeur du Centre Viet Nam,Rhizomys sinensis ou rat de bambou, provoquant la mortalité de cet animal en captivité,2) Ce champignon est expérimentalement pathogène pour la souris le hamster et le rat, atteints d'une réticulose macrophagique semblable à l'histoplasmose ou à la leishmaniose.3) Le champignon se développe dans les cellules réticulaires où il se présente sous forme ronde, ovale ou légèrement allongée. Il se multiplie par cloisonnement transversal.4)En culture à 37°,P. marneffei donne des cultures glabres, lisses ou plissées, de consistance crémeuse, ressemblant à une culture bactérienne et formées d'arthrospores.5)Par ses caractères botaniques, le champignon doit être considéré comme une espèce nouvelle, à rapprocher deP. janthinellum et deP.citrinum.
Summary 1) A new species ofPenicillium, P. marneffei Segretain, Capponi, Sureau, has been isolated from a rodent of the center of Viet Nam,Rhizomys sinensis or bamboo rat; it causes the death of this animal living in captivity.2) This fungus is experimentally pathogen for mice, hamsters and rats: it produces a reticulosis similar to histoplasmosis or leishmaniosis.3) The fungus grows in the reticulo-endothelial cells in which its form is round, oval or slightly elongated. It multiplies by scissiparity.4) At 37° C the colony ofP. marneffei is glabrous, smooth or folded, resembling that of Bacteria and formed by arthrospores.5) By its botanical caracters, the fungus is considered as a new species to be classed nearP. janthinellum andP. citrinum.
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Summary The regeneration (organogenesis was studied by Emig, 1972 a, b) of Phoronida can be divided into three phases: the first one, cicatrisation, is characterized by a provisional mesodermal scar-tissue, later the old epidermis cover this scar-tissue. The regenerating blastema, second phase, takes place by cellular dedifferentiation processes; each germ layer (ectoderm, mesoderm, endoderm) regenerates itself from its own elements. One exception only seems to be oesophagel regeneration by metaplasia of the prestomacal cells during the asexual reproduction. The differentiation of the amputated structures (third phase) appears submitted to the inductive influence of the mesoderm and to the trophic action of the nervous system (especially the epithelial plexus). The polarity in regeneration sets a problem in Phoronida.

Ce travail a été effectué dans le cadre du contrat L. A. n 41 au C. N. R. S.  相似文献   

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