The tail of Ascaphus : a historical resume and new histological-anatomical details

Van Dijk, D. E. (D. Eddie) (1954-12)

Thesis (MSc)-- University of Stellenbosch, 1954

Published in the Annals of the University of Stellenbosch, Volume 31, Section A, No.1 (1955)

Thesis

ENGLISH ABSTRACT: The pelvic girdles of the two anuran genera Ascaphus and Leiopelma of the family Ascaphidae are very similar. Attached to them by cartilage (or connective tissue in some Ascaphus specimens) is a cartilaginous, in Leiopelmu somewhat ossified, epibubis. In Ascaphu8, as in Xenopus, the epipubis originates from two Anlages, and its muscles are also paired in the Ascaphidae, while in Xenopus only one is present, although this also appears to originate (rom two muscles. The cloaca extends behind the pelvic girdle in both sexes in Al:lcaphus, and it is supported by two rods consisting of strong connective tissue (Faserknochen?). These rods are attached to the ventral surface of the pelvic girdle, in the female closely, in the male by means of tendons. Between the rods and the epipubis a broad tendinous band extends, which is thick in the male; in the latter the mm. compressores cloacae have their origins posteriorly on the rods, while in the female the rods are completely imbedded in these muscles posteriorly. In the female particularly there are transverse muscle fibres which are not striped although probably derived from the mm. compressorcs cloacae. Behind the pelvic girdle there is cavernous tissue in both layers of the tunica muscularis, and ventrally it covers the mm. eompressores cloacae. The circular and longitudinal muscle layers are poste riorly separated by gliding planes. The cloaca is supplied by branches of the a. mcsenterica posterior and the au. pudendae anteriores, and is drained by the vv. pudendae and a small medial v. eaudalis. The cloaca is innervated dorsally by the plexus ischio·coccygeus and ventrally by a branch of the n.ischiadicus (the n. pudendus). The cloaca of the male serves as a copulatory organ. There is internal fertilization.

No Afrikaans abstract available.

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