摘要:

A histological examination has been made of the reproductive organs of the Skomer vole to study the reproductive cycle and fertility of this race of the Bank vole (Clethrionomys glareolus) in its insular habitat. The main aim of the work was to compare the cycle with that ofClethrionomyson the mainland of Britain which was similarly investigated by Brambell&Rowlands (1936).

ISSN:0952-8369    

DOI:10.1111/j.1469-7998.1969.tb04963.x

出版商:Blackwell Publishing Ltd    

年代:1969

数据来源: WILEY

摘要:

The reproductive organs of wild and park female Fallow deer have been examined. The deer appear to breed for the first time in their second year when they are about 16 months old; none of the fawns examined was pregnant. All the adult deer had ovulated and about 95% were pregnant. It is concluded that most adult Fallow deer breed each year. The only difference found between wild and park deer was in the incidence of transmigration of the ovum; this being 52% and 28% respectively.

ISSN:0952-8369    

DOI:10.1111/j.1469-7998.1969.tb04964.x

出版商:Blackwell Publishing Ltd    

年代:1969

数据来源: WILEY

摘要:

Breaks in the distribution of forest mammals (of which the best data are for the primates), frogs and cyprinodont fishes and their subspeciations have been attributed by authors to the barriers presumably presented by a savanna gap formed by past extension of the Baoule V in the Côte d'Ivoire, by the present Dahomey Gap and by the course of the lower Niger. The potentials of these three features are considered and their history is discussed in the light of up‐to‐date geological and palaeo‐climatological information. As part of the back‐ground, evidence for the rate at which evolution can occur is summarized. The distributional data for each of the three classes and also for birds are then set out. Each class of animal is found to show different problems at taxonomic levels from the subspecies

ISSN:0952-8369    

DOI:10.1111/j.1469-7998.1969.tb04965.x

出版商:Blackwell Publishing Ltd    

年代:1969

数据来源: WILEY

摘要:

A list of the species now included in the genus is given with notes of their geographical distribution and (where possible) details of their ecology and a key for their identification. An amended diagnosis of the genus is given to include two new species, hitherto unnamed and known only from damaged and inadequate material, which are now named and fully described and figured.

ISSN:0952-8369    

DOI:10.1111/j.1469-7998.1969.tb04966.x

出版商:Blackwell Publishing Ltd    

年代:1969

数据来源: WILEY

摘要:

The morphology and its variation of the bony pelvis in British species of Muridae and Cricetidae have been studied. The investigation began with the application of a mensural method for demonstrating sexual dimorphism and it is shown that for all species except those ofRattusthe male os coxa can be distinguished from the female over a wide range of ages. During the study it became obvious that there are ranges of morphological variation in os coxae both inter‐ and intraspecific. There are constant interpecific differences which allow identification of os coxae of these rodents at least to genus and in many cases to species. Detailed descriptions of the morphology of the os coxa of each species are given together with an identification key. Intraspecific variation is mainly sex‐dependent and comprises sexual dimorphism, male pubertal changes and female parturition changes. The changes in the male are from epicene, through pubertal, to post‐pubertal phase, with the first of these resembling the agonadal, female, form and the last with a posterior border thickened and tuberculate in relation to the hypertrophied penis and its associated glands and musculature. These phases are not equally obvious in all species, but the pelvis in all exceptRattusandMusshows some evidence of the sexual development of the animal. In females the form of the pelvis may be modified during successive pregnancies to allow a wider pelvic outlet for parturition. Resorption and remoulding of the female pelvis allows the recognition of non‐parous, uniparous and multiparous animals in all Cricetid species, inMicromysand, more doubtfully, inMus, but not inApodemusandRattus. Non‐sex‐dependent intraspecific variation, comprising differences in rugosity related to muscularity is also described.The observations are discussed in relation to earlier experimental work, to the need for basic research on small mammal reproduction and population structure, and to the use of the pelvis in the analysis of osteological assemblages, such as occur in

ISSN:0952-8369    

DOI:10.1111/j.1469-7998.1969.tb04967.x

出版商:Blackwell Publishing Ltd    

年代:1969

数据来源: WILEY