. The biology of the amphibia. Amphibians. In the cloaca of the female salamander all three sets of glands may appear, although here they have different functions. The pelvic gland serves as a res- ervoir for the spermatozoa which migrate from the dis- integrating spermatophore held between the lips of the cloaca to these tubules in the roof of the cloaca (Noble and Weber, 1929). The cloacal glands which are present in all ambystomids, salamandrids, and primitive plethodontids, may play some part in egg- capsule formation. The ab- dominal glands are also de- veloped in female newts. They
. The biology of the amphibia. Amphibians. In the cloaca of the female salamander all three sets of glands may appear, although here they have different functions. The pelvic gland serves as a res- ervoir for the spermatozoa which migrate from the dis- integrating spermatophore held between the lips of the cloaca to these tubules in the roof of the cloaca (Noble and Weber, 1929). The cloacal glands which are present in all ambystomids, salamandrids, and primitive plethodontids, may play some part in egg- capsule formation. The ab- dominal glands are also de- veloped in female newts. They are present in Amby- stoma,Necturus,and Eurycea, although apparently rudimen- tary and non-functional. Their homologies with the male glands have been estab- lished by transplanting a testis into the body of the female. The spermatheca in the newt then changes into the pelvic gland, the rudimentary ab- dominal glands into a func- tional organ (Beaumont, 1928). It is interesting that in Desmognathus, where neither abdominal nor cloacal glands are present even as rudiments in the female, the same operation causes these two glands to sprout de novo from the undifferentiated epi- thelium of the cloaca of the adult female (Noble and Pope, 1929). Thus, even in the higher plethodontids the abdominal and cloacal. Fig. 103.—Diagrammatic sagittal sec- tion of the cloacas of three salamanders to show the evolution of the spermatheca. Anterior end on the left. (Based on data from Kingsbury and from Dieckmann.) A. Necturus. Spermatheca tubules nu- merous and opening on the roof of the cloaca. B. Ambystoma. Tubules less numerous and opening into a common duct. C. Desmognathus. Showing fur- ther reduction and modification of the tubules, also loss of dorsal and ventral glands. , common tube of spermathe- ca; , dorsal gland; Sp., spermatheca; , ventral Please note that these images are extracted from scanned page images that may have been digitally enhanced for readabil
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Keywords: ., bookcentury1900, bookpublishernewyorkmcgr, booksubjectamphibians
