摘要:

The paper deals with a biometrical analysis of forty‐one specimens of the Gwyniad,Coregonus clupeoides pennantii(Cuv. et Val.) of Bala Lake, (Llyn Tegid) North Wales. Tho Gwyniad shows the greatest relationship to the continental coregonidsCoregonus lavaretus. It is proposed that the taxonomy of the British whitefishes be revised and that the Gwyniad be classified asCoregonus lavaretus pennantii(Cuv. et Val.). Similarly, it is proposed that the Powan of Loch Lomond be classified asCoregonus lavaretus clupeoidesLacépède. The classification of the Schelly from the English Lake District needs further investigat

ISSN:0370-2774    

DOI:10.1111/j.1469-7998.1965.tb01996.x

出版商:Blackwell Publishing Ltd    

年代:1965

数据来源: WILEY

摘要:

Eggs ofCulex pipiensL.are laid in rafts on the surface of still or slow moving water, whereas those ofMansonia africana(Theobold) are deposited beneath tho surface of the water on the undersides of floating leaves (Laurence&Smith 1958; Laurence 1959). The eggs of both species are surrounded by air, those ofCulex pipiensare in direct contact with the external atmosphere, whereas those ofMansonia africanaare partially surrounded by a bubble of air trapped between them. The anterior onds of the eggs ofMansonia africanaproject through the bubble of air into the surrounding water. This bubble of air is only found around living eggs and disappears if tho eggs die and shortly before they hatch. Iyengar (1935) has shown that the eggs ofFicalba minimaTheo. although often deposited on the same leaf as those ofMansonioides, are laid above the water line and resemble in structure those ofCulexandCoquillettidia. The structure of the egg‐shell of bothCulez pipiensandMansonia africanais described and discusse

ISSN:0370-2774    

DOI:10.1111/j.1469-7998.1965.tb01997.x

出版商:Blackwell Publishing Ltd    

年代:1965

数据来源: WILEY

摘要:

The structure and functioning of the gut ofPomacea canaliculata(D'Orb.) has been investigated using living and preserved material. Anatomical studies were also carried out on preserved specimens ofPila globosa, Turbinicola saxea and Lanistes ovum bangweolicus.The gut of pilids is specialised for a macrophagous diet, usually of aquatic angiosperms. The mid‐oesophagus is a crop for storage, and the stomach has a large triturating gizzard developed from the gastric shield area. This is the site of extra‐cellular digestion; there is no intra‐cellular digestion in any part of the gut. The ducts of the digestive gland open into a special region of the stomach, the vestibule, which is histologically similar to them. The style sac begins the compacting of the faeces, which is completed in tho intestine. There is no evidence that absorption ocrurs in the epithelium of tho stomach or intestine; soluble products of digestion are carried into the digestive gland, which is the main site of absorption. Its activity is supplemented by amoebocytes entering the lumen of the style sac and intestine. Two types of cell occur in the gland, one type producing digestive enzymes and absorbing soluble products of digestion, the other type being excretory in function. There is no sign of phagocytosis in either. The excretory activity of the kidney is further supplemented by an anal

ISSN:0370-2774    

DOI:10.1111/j.1469-7998.1965.tb01998.x

出版商:Blackwell Publishing Ltd    

年代:1965

数据来源: WILEY

摘要:

A 1‐month survey of the vervet monkeys of Lolui, an uninhabited island of 11 square miles in Lake Victoria, indicated a population size of about 1,500. Reliable counts of 46 groups were made, giving a mean of 12. Age and sex analyses of 18 groups showed a ratio of 1: 1.4 adult males to adult females, 1: 1 for adults and immatures combine

ISSN:0370-2774    

DOI:10.1111/j.1469-7998.1965.tb01999.x

出版商:Blackwell Publishing Ltd    

年代:1965

数据来源: WILEY

摘要:

The musculature of the fourth to eighth abdominal segments is typically composed of twenty pairs of segmental muscles associated with the body wall. In the first to third and ninth and tenth segments certain modifications to the basic plan occur in association with the abdominal‐thoracic junction, the respiratory apparatus and the anal appendages. In some segments there are also paired muscles associated with the alimentary canal. Two large transverse muscles are present in the abdomen. There are eight abdominal ganglia, the first seven of which each give rise to three pairs of lateral nerves, the eighth to five pairs. In addition there are ten median abdominal nerves. The innervation fields of the various nerves are described. The first three pairs of lateral nerves of the last ganglion are homologous with the lateral nerves of the other abdominal ganglia; the fourth pair innervates most of segment nine; and the fifth pair innervates the remainder of segment nine, segment ten and the anal appendages. Certain of the abdominal muscles are innervated by branches from two different nerve roots. In segments six and seven the anterior point of attachment of the longitudinal stretch receptors is normally different from that in the other abdominal segments. This is discussed in the light of the types of movement which involve the abdomen and it seems apparent that these receptors are affected not only by swimming and abdominal flexion, as are the other longitudinal stretch receptors, but also by respiratory movements. Two distinct types of epidermal sensilla are present on the abdomen, spines and hairs. The former are the more numerous on the body, the latter on the anal appendage

ISSN:0370-2774    

DOI:10.1111/j.1469-7998.1965.tb02000.x

出版商:Blackwell Publishing Ltd    

年代:1965

数据来源: WILEY

摘要:

The web structure and the web spinning process ofLatrodectus tredecimguttatusRossi,Latrodectus pallidusCambridge andLatrodectus revivensisShulov have been investigated, particular attention being given to the structure of their catching webs.The webs ofLatrodectusrepresent a further development of the web‐type ofArchaeranea tepidariorum. The specific characters of the investigated webs concern the middle layer of their three‐layer webs, where more or less regular structures appear.In the middle layer ofL. tredecimguttatusweb paths of hexagonal meshes appear.In the web ofL. pallidusandL. revivensismore or less regular radially arranged catching platforms appear, connected with the distant retreat by a long bridge‐web.The lower layer of vertical threads, with viscid droplets on their far ends is spread‐out inL. tredecimguttatusand consists of short threads as distinct from the concentrated bundle of high threads in the two other species.SinceL. pallidus and L. revivensisappear usually among vegetation, their restricted catching webs seem to be adaptive adjustment to the biotope.The concentration of the catching webs brings about improvement as regards prey detection.The differences in the web structure ofL. tredecimguttatusandL. revivensisindicate that their behavioural characters are more distinct than the morphological ones. The different behavioural characters support the view thatL. revivensis represents a species different from L. mactans tredecimg

ISSN:0370-2774    

DOI:10.1111/j.1469-7998.1965.tb02001.x

出版商:Blackwell Publishing Ltd    

年代:1965

数据来源: WILEY

摘要:

The taxonomic status of the Hylid frogsHyla serrataAndersson andH. nannotisAndersson of Queensland, andH. eucnemisLönnberg andH. obsoletaLönnberg of New Guinea has been the subject of controversy, Loveridge (1935), Copland (1957), Moore (1961).The author has examined the type specimens of the above species and all other available material in an attempt to clarify their taxonomic status. On the basis of this investigation of morphological variation, the following changes to currently recognized generic and specific names are proposed:Hyla obsoletaLönnberg =Nyctimystes obsoleta(Lönnberg),Hyla rhacophorusVan Kampen =Hyla eucnemisLönnberg,Hyla serrataAndersson =Hyla eucnemisLön

ISSN:0370-2774    

DOI:10.1111/j.1469-7998.1965.tb02002.x

出版商:Blackwell Publishing Ltd    

年代:1965

数据来源: WILEY

摘要:

The process of shell repair in specios ofAnodontais re‐examined in the light of current views on the mantle/shell relationship in the Lamellibranchia. Experiments indicate that the epithelia of the general outer mantle surface and mantle isthmus normally responsible for the production, respectively, of the inner layer of the valves and of the ligament can regenerate material comparable with that produced by the outer fold of the mantle edge. The process, which is usually preceded by a phase in which amoebocytes are involved, consists initially of the formation of appreciable quantities of organic material (conchiolin). Much of this conchiolin is histochemically comparable with that of the periostracum and the outer layers of the valves and ligament secreted during marginal increment of the shell by the inner and outer surfaces, respectively, of the outer mantle fold. This type of conchiolin is probably rich in quinone‐tanned protein (sclerotin). Repair of the valves is completed by the calcification of this organic matrix to form an outer calcareous (prismatic) layer, followed by the desposition of inner (nacreous) layer material.During the repair process, the form of the general outer mantle epithelium tends to vary according to the type of material being secreted. While regenerating periostracal and outer shell layer components the epithelial cells of the general outer mantle surface and mantle isthmus resemble both histologically and histochemically those of the outer fold of the mantle edge. Completion of valve repair by the deposition of nacre is accompanied by the cells reverting to the form characteristic of the general mantle surface during normal shell growth.InAnodontaand related bivalves, therefore, the relationship which normally exists between the different shell layers and the secretory epithelial zones of the mantle does not appear to be specific and unalterable. The implications of these findings in relation to marginal growth of the mantle and shell are discus

ISSN:0370-2774    

DOI:10.1111/j.1469-7998.1965.tb02003.x

出版商:Blackwell Publishing Ltd    

年代:1965

数据来源: WILEY

摘要:

Certain quantitative features of the primato scapula bear no obvious mechanical relevance to such functions of the bone as are known to be significant in the employment of the forelimb during progression. Statistically these “residual” features are but weakly correlated with those of established locomotor significance and do not show a correspondingly regular pattern of contrast between Primates in different locomotor categories.These features would, therefore, appear not to be adapted to locomotor function. Consequently, unless they have other functional significance or are linked genetically with other adaptive characters, their parallel variation may indicate genetic relationship. Thus, residual metrical features of this type may be of significance in primate classification. This is in contrast to features of proved locomotor significance whose concurrent appearance in several groups probably represents the result of parallel selection acting in unrelated species.Eight such features examined in thirty genera (covoring most of the primate order) differentiate significantly between genera within subfamilies and somewhat fewer features differentiate between the components of progressively higher taxonomic groups. But the degree of overlap between genera is such as to minimize the value of individual dimensions in classifying an unknown specimen. It would, however, seem likely that the combination of these dimensions by multivariate techniques might effect a more efficient separation of forms within the primate or

ISSN:0370-2774    

DOI:10.1111/j.1469-7998.1965.tb02004.x

出版商:Blackwell Publishing Ltd    

年代:1965

数据来源: WILEY

ISSN:0370-2774    

DOI:10.1111/j.1469-7998.1965.tb02005.x

出版商:Blackwell Publishing Ltd    

年代:1965

数据来源: WILEY