摘要:

AbstractThe anatomy of the head and the structure of the mouthparts is described for calypterate larvae of differing feeding habits.The way in which the skeletal parts of the cephalopharynx and the musculature are adapted to the type of food is discussed and particular reference is made to the action of the mouthparts in the carnivorous larva ofLimnophora ripariaFallen.

ISSN:0001-7272    

DOI:10.1111/j.1463-6395.1971.tb00556.x

出版商:Blackwell Publishing Ltd    

年代:1971

数据来源: WILEY

摘要:

AbstractThe endocranium of Devonian osteolepiforms includes four minor structures, called zygals, which probably represent cephalic vertebral elements belonging to the second, third, and fourth metameres. Also, the endocranium exhibits a partial segmentation in the form of vestiges of intrametameric articulations attributable to the anterior five metameres. Finally, the basicranial muscle of osteolepiforms, extending across the lower part of the endocranial articulation within the second metamere, is possibly supplied by a separate cranial nerve, for which the termnervus rarusis proposed. This hypothetical cranial nerve, which in osteolepiforms possibly emerges from the endocranium through a canal in the fourth metamere, is suggested to constitute, together with the trochlear nerve, the somatic motor component of the second cranionerval segment.

ISSN:0001-7272    

DOI:10.1111/j.1463-6395.1971.tb00557.x

出版商:Blackwell Publishing Ltd    

年代:1971

数据来源: WILEY

摘要:

AbstractDistributional pattern of the neuromasts has been described forGobius striatusDay. The neuromasts are arranged in several lines. Canal formation, like many gobiids, is suppressed to varying extent. The supraorbital line presents interesting variations. The supraorbital lines of the two sides are separate from each other even in the so‐called common ‘interorbital chamber’. An outstanding feature of the neuromast system of the fish is the great development of the supramaxillary line which is perhaps best developed in this

ISSN:0001-7272    

DOI:10.1111/j.1463-6395.1971.tb00558.x

出版商:Blackwell Publishing Ltd    

年代:1971

数据来源: WILEY

摘要:

AbstractThe hypothalamo‐neurohypophysial (HN) complex ofMacrognathus aculeatusis described with the help ofin situstaining technique and tissue sections. Bulk stained preparations provide a three‐dimentional view of the entire HN complex. The nucleus preopticus (NPO) which is oval in the ventral view appears boat‐shaped in the cross sectional view of thein totostained brain. But it is in the form of an inverted L in median parasagittal section. Both pars magnocellularis and parvocellularis contribute fine fibers towards the formation of the right and the left main tracts which are composed of groups of loosely set bundles of axons. Unlike the earlier reported cases the main tract in this species runs lateral to the pituitary axis and independently enters it at the level of the proximalpars distaliswithout forming a common neurosecretory tract which is a feature not yet well known.In situdemonstration of the neurosecretory system inM. aculeatushas clearly revealed certain complex features which are difficult or impossible to understand through reconstruction studies of tissue sections. Extension of suchin situstaining techniques to other species of teleosts may provide a wide variety of variations in the distributional patterns of their neurosecretory tracts which might throw additional light on the function and evolution of this s

ISSN:0001-7272    

DOI:10.1111/j.1463-6395.1971.tb00559.x

出版商:Blackwell Publishing Ltd    

年代:1971

数据来源: WILEY

摘要:

AbstractAn air drying method for karyotype analysis of Planarian worms is described. Five species are analysed (D. lugubris, D. tigrina, D. gonocephala, C. alpinaandP. felina).Some differences and similarities are detected, both in quantitative and qualitative respects. All the chromosomes can be clearly identified. The haploid number ranges from 4 to 9. An attempt to tackle the difficult problems of phylogenic aspect, and chromosomal variation in the somatic cells ofD. gonocephala, is presented.RésuméLes auteurs présentent une technique d'analyse du caryotype des Planariidae, par choc hypotonique.Les caryotypes de 5 espèces (D. lugubris, D. tigrina, D. gonocephala, C. alpinaetP. felina) sont décrits et comparés.Des différences et des analogies sont ainsi mises en évidence dans le genre Dugesia, où une étude phylogénique est ébauchée.Le problème de la variation chromosomique des lignées somatiques, chezD. gonocepha

ISSN:0001-7272    

DOI:10.1111/j.1463-6395.1971.tb00560.x

出版商:Blackwell Publishing Ltd    

年代:1971

数据来源: WILEY

摘要:

AbstractThe modifications noticed in the caudal musculature of the South Indian Flying Lizard,Draco dussumieri, are described. The caudal musculature consists of the superficialilio‐caudalisandischio‐caudalisand the deeper ventralcaudo‐femoralis brevisandcaudo‐femoralis longus. There is an accessory tendon extending between the outer border of the tendon of thecaudo‐femoralis longusand the tendinous origin of thegastrocnemius.In the male the copulatory organ is provided with a retractor muscle. Attached to the ventral surface of the penis sheath is another muscle which helps in everting the penis. This latter muscle is present in the female also as a vestigeal one attached to the postero‐lateral corners of the cloacal chamber.The modifications in the caudal musculature are attributable to the gliding habits of this lizard.Draco dussumieri, the South Indian Flying Lizard is unique in having a patagium for gliding from tree to tree. Associated with the development of the patagium, the musculature has undergone a number of adaptive modifications. The modifications of the trunk musculature have been published elsewhere (John 1970). The present communication is a study of the caudal musculature of

ISSN:0001-7272    

DOI:10.1111/j.1463-6395.1971.tb00561.x

出版商:Blackwell Publishing Ltd    

年代:1971

数据来源: WILEY

摘要:

RésuméLe complexe neural deCiona intestinalisa été fixé toutes les deux heures entre 2 h. et 24 h., puis examiné aux microscopes photonique et électronique. Au cours de cette période, la glande neurale subit des transformations qui la font passer d'un état épithélial (phase réticulée) à un état mésenchymateux (phase compacte), puis, après l'élimination d'une partie du matériel cellulaire disloqué et accumulé dans la région centrale, elle retrouve, par la périphérie, un état épithélial (phase réticulée périphérique). Ces transformations cycliques se produisent deux fois en 24 heures.Le passage des cellules d'une forme cubique à une forme étoilée a été décrit. Cependant la destinée des cellules libérées reste encore hypothétique et le problème d'une fonction exocrine ou d'une fonction endocrine de la glande est posé.La tunique fibreuse associée à la membrane entourant les lames glandulaires a été décrite et son rôle dans le transfert à la glande de granules de neurosécrétion en provenance des extrémités axoniques a été envisagé.AbstractThe neural complex ofCiona intestinalishas been fixed every two hours between 2 a.m. and 12 p.m. During this period, the neural gland undergoes morphological changes, turning from an epithelial structure (reticulate stage) to a mesenchymal structure (compact stage). After the elimination of part of the cellular material which had been disrupted and accumulated in the central area of the gland, it recovers an epithelial structure, starting from the periphery (peripheric reticulate stage). These cyclic changes occur twice in 24 hours.The ultrastructural changes that characterize the transformation from cubic to stellate shape of the glandular cells have been described. However the fate of the loose cells is still hypothetical and the question of the exocrine or endocrine function of the gland remains unanswered.The fibrous tunic associated with the membrane around the glandular laminae has been described and its possible role in the transfer of neurosecretory granules

ISSN:0001-7272    

DOI:10.1111/j.1463-6395.1971.tb00562.x

出版商:Blackwell Publishing Ltd    

年代:1971

数据来源: WILEY

摘要:

AbstractThe prolactin‐producing cells inClupea harengus membras, Polypterus palmasandCalamoichthys calabaricushave been localized by fluores‐ceinlabelled antibodies to ovine prolactin.Pituitary sections were cut in a cryostat and both direct and indirect protein tracing methods have been used. As an additional method the paraffin embedding technique was carried out withPolypterus palmas. The prolactin‐producing cells inClupea harengus membraswere localized to the follicle epithelium in the rostral pars distalis. InPolypterus palmasandCalamoichthys calabaricusthe prolactin producing cells were scattered all over the pars distalis.A possible relationship between the erythrosinophilic prolactin cells and the epithelium cells in the buccohypophyseal canal is disc

ISSN:0001-7272    

DOI:10.1111/j.1463-6395.1971.tb00563.x

出版商:Blackwell Publishing Ltd    

年代:1971

数据来源: WILEY

摘要:

AbstractThe outer segment of long and short photoreceptors in the retina of the river lamprey,Lampetra fluviatilis, were studied by light‐ and fluorescence microscopy together with some different electron microscopic methods. The outer segments show characteristics of both rods and cones and are suggested to represent intermediate kinds of photoreceptor

ISSN:0001-7272    

DOI:10.1111/j.1463-6395.1971.tb00564.x

出版商:Blackwell Publishing Ltd    

年代:1971

数据来源: WILEY

摘要:

AbstractThe ultrastructure of the paired nerves, previously called frontal organ or X‐organ, in copepod crustaceans was investigated. These nerves, running from the anterior margin of the brain to the frontal edge of the animals, are found to contain the dendrites of three types of morphologically different sensory neurons. The first unit consists of two dendrites (distinguished by their myelinization) leading to two small hairs on the front. Their detailed structure was not investigated. The second unit consists of a few large dendrites ending in branching cilia. The latter are surrounded by a specialized glial cell. The ciliary branches are regularly sized and arranged. The third unit consists ofc. 17 dendrites ending with cilia at the cuticle. The cilia are split into irregular branches which are buried in modified epidermal cells which, in the case ofCalanus, are connected with cuticular pores.By analogy with other presumed chemosensory organs in the Arthropoda, the second and the third unit are considered, on a morphological basis, to be chemoreceptors. The second unit receives internal stimuli. Because it resembles other X‐organs in the Crustacea, all X‐organs could have the same function. The third unit is thought of as receiving external st

ISSN:0001-7272    

DOI:10.1111/j.1463-6395.1971.tb00565.x

出版商:Blackwell Publishing Ltd    

年代:1971

数据来源: WILEY