ISSN:0370-2774    

DOI:10.1111/j.1469-7998.1934.tb06214.x

出版商:Blackwell Publishing Ltd    

年代:1934

数据来源: WILEY

ISSN:0370-2774    

DOI:10.1111/j.1469-7998.1934.tb06215.x

出版商:Blackwell Publishing Ltd    

年代:1934

数据来源: WILEY

ISSN:0370-2774    

DOI:10.1111/j.1469-7998.1934.tb06216.x

出版商:Blackwell Publishing Ltd    

年代:1934

数据来源: WILEY

摘要:

Summary.In a llama the spinal portion of the accessory nerve was grossly absent. The sterno‐cephalic muscle was innervated by the second cervical nerve and, presumably, also by a branch from the bulbar portion of the accessory nerve.Consideration of the literature indicates that the gross morphology of the accessory nerve and its relation to the sterno‐cephalic and brachio‐cephalic muscles are extremely variable features in the longest‐necked ungulates (giraffe, camel, llama).Bibli

ISSN:0370-2774    

DOI:10.1111/j.1469-7998.1934.tb06217.x

出版商:Blackwell Publishing Ltd    

年代:1934

数据来源: WILEY

ISSN:0370-2774    

DOI:10.1111/j.1469-7998.1934.tb06218.x

出版商:Blackwell Publishing Ltd    

年代:1934

数据来源: WILEY

ISSN:0370-2774    

DOI:10.1111/j.1469-7998.1934.tb06219.x

出版商:Blackwell Publishing Ltd    

年代:1934

数据来源: WILEY

摘要:

Summary.1By tagging individual frogs in a pond it was found that the males, after mating once, remained behind in the pond with the other males, and often mated several times in one season. Other males did not secure mates at all. Pairs remained in amplexus under natural conditions less than twenty‐four hours.2The recognition of the female by the male depends primarily on the rough granules of her skin, which are developed during the breeding season, a different method of sex recognition from any hitherto described. She is retained after seizure because she remains silent and has a stout figure. When she lays her eggs she is released by the automatic cessation of the impulse to grip, resulting from her diminished size, aided by the use of her voice.3The female assists the expulsion of her eggs by pressing her hands on her abdomen and forcing them out.4The sperm‐emission stimulus is merely the contact of the eggs with the symphysis pubis region of the male.5The males struggle for the possession of the females by using their feet to push away or force off their opponents, especially by hooking their toes under the encircling arms of the other frog. This appears to be the only point at which the nuptial pads perform a useful funct

ISSN:0370-2774    

DOI:10.1111/j.1469-7998.1934.tb06220.x

出版商:Blackwell Publishing Ltd    

年代:1934

数据来源: WILEY

摘要:

Summary.1Oviposition in the toad is preceded by a stretching action of the female, which warns the male that laying is about to commence. He responds by placing his toes so that they feel the eggs emerging. This acts as a sperm‐emission stimulus.2The male is discharged by the female at the conclusion of oviposition by a repetition of the oviposition warning. Since there are no eggs the chain of instinctive reactions in the male is broken, and he leaves go and swims away.3Sex recognition depends on the voice, possessed by the male but not by the female, and on the dodging, repulsive action which males show when seized.4Fighting is vigorous, and is conducted mainly by the attacking toad forcing himself between the pair from behind. Defence is1 carried out by thrusts of the fee

ISSN:0370-2774    

DOI:10.1111/j.1469-7998.1934.tb06221.x

出版商:Blackwell Publishing Ltd    

年代:1934

数据来源: WILEY

摘要:

Summary.1. An external spinal accessory nerve was lacking in a bactrian camel which was available for study. Nevertheless the accessory nerve had a spinal origin which extended downwards into the second cervical segment. The ascending stem of the nerve joined the 10th nerve, and sent branches into the posterior roots of the first and second cervical nerves.2. The sterno‐cephalic and brachio‐cephalic muscles were supplied by cervical ner

ISSN:0370-2774    

DOI:10.1111/j.1469-7998.1934.tb06222.x

出版商:Blackwell Publishing Ltd    

年代:1934

数据来源: WILEY

摘要:

Summary.The morphology of the freshwater medusa,Limnocnida rhodesiœBoulenger, obtained from new sites in the Zambesi and Limpopo river‐systems, is described and illustrated by photographs (Pl. I.).The new sites forL. rhodesiœare the Prince Edward Dam on the Hunyani River, near Salisbury, the Hartebeestpoort Dam on the Crocodile River, near Pretoria, and the Bezuidenhout Valley in Johannesburg.The range of dimensions ofL. rhodesiœis extended, the present specimens being larger than those previously described.The specimens ofL. rhodesiœexamined from the new localities were all females in active egg‐production. Manubrial bud‐formation was seen in only a few specimens.A species ofTrichodinaoccurred in small numbers on the external surface and tentacles ofL. rhodesiœfrom the new localities cited.Some ecological notes onLimnocnidaare given.The present geographical distribution of the genusLimnocnidais discussed and the continued southward range of distribution in Africa from Lake Victoria Nyanza to Johannesburg is detailed. Similarly, the distribution of the known species ofLimnocnidais given,L. tanganicœ, the Central African form, being replacedby L. rhodesiœin Rhodesia and the Transvaal, andby L. indicain India.The possible significance of the present‐day geographical distribution ofLimnocnidain relation to former geological conditions on the earth's surfac

ISSN:0370-2774    

DOI:10.1111/j.1469-7998.1934.tb06223.x

出版商:Blackwell Publishing Ltd    

年代:1934

数据来源: WILEY