On the cloacal region of Anura in particular of larval Ascaphus

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dc.contributor.advisor De Villiers, C. G. S.
dc.contributor.author Van Dijk, D. E. (D. Eddie)
dc.contributor.other University of Stellenbosch. Faculty of Science. Dept. of Botany and Zoology
dc.date.accessioned 2011-08-03T12:23:12Z
dc.date.available 2011-08-03T12:23:12Z
dc.date.issued 1959-12
dc.identifier.uri http://hdl.handle.net/10019.1/16042
dc.description Thesis (DSc)--University of Stellenbosch, 1959 en_ZA
dc.description Published in the Annals of the University of Stellenbosch, Vol. 35, Sect. A, No.4 (1959)
dc.description.abstract ENGLISH ABSTRACT: The ontogeny of the cloacal region of Ascaphus is described from limited larval material (beginning approximately at the stage of hind-limb bud development). A comprehensive series of Bufo angusticeps larvae and late pre-larval embryos were used for comparison. The adult and/ or late larval conditions of the cloacal region in Ascaphus, Bufo, Bombina, Leiopelma, Rana and Xenopus arc compared. The rods of Noble supporting the cloaca in Ascaphus and the tendinous sheet connecting these with the epipubis are shown to be modifications of an interfemoral ligament present, with thickened lateral margins, in all the Anura studied. The cloacal lips differentiate early in metamorphosis in Ascaphus and Bufo and bear similar relations to the interfemoral ligament in these and other Anura, so that they are apparently homologous. The posterior part of the urodaeum is lengthened in the adult male Ascaphus to form the "tail" (phallus). The hind-limb anlagen of Ascaphus appear directly beneath the spinal myomeres and immediately behind the posterior tips of the abdominal muscle cords. In Ascaphus, Bufo and Bombina the abdominal muscles (metamerically disposed in Ascaphus and Bufo) are initially attached posteriorly to the spinal myomeres but are separated from them anteriorly. lt is probable that the mm. compressores cloacae are derived from the hind-limb anlagen. In all Anura examined, including members of all the South African families, the a. ischiadica and n. ischiadicus have a small muscle (designated m. circumflexor arteriae) associated with them; it is presumably capable of compressing the artery against the nerve. The cloacal region of Ascaphus appears to be less specialized than that of Rana and Xenopus, contrary to what is generally believed for the last two genera. Bufo, particularly and Bombina have undergone less specialization. en_ZA
dc.description.abstract No Afrikaans abstract available. en_ZA
dc.format.extent p. 169-249 : ill.
dc.language.iso en_ZA en_ZA
dc.publisher Stellenbosch: University of Stellenbosch en_ZA
dc.subject Anura -- Anatomy en_ZA
dc.subject Frogs en_ZA
dc.subject Ascaphus -- Anatomy en_ZA
dc.subject Dissertations -- Zoology en_ZA
dc.subject Theses -- Zoology en_ZA
dc.subject Cloaca (Zoology) en_ZA
dc.title On the cloacal region of Anura in particular of larval Ascaphus en_ZA
dc.title.alternative Annals of the University of Stellenbosch, Volume 35, Section A, No.1 (1959) en_ZA
dc.type Thesis en_ZA
dc.rights.holder University of Stellenbosch en_ZA
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