. The biology of the amphibia. Amphibians. THE MODE OF LIFE HISTORY 71 There is one genus of Brachycephalidae, Rhinoderma (Fig. 25), which has attracted attention for many years because the male carries the eggs in his vocal pouch until they hatch as fully formed frogs. The tadpoles during this period have typical larval mouth parts, although these remain uncornified. The papillae about the mouth resemble more closely those of the bufonid Paludicola, as described by Fernandez (1927), than those of the brachycephalid Dendrophry- niscus stelzneri, described by the same author. No inter- mediate
. The biology of the amphibia. Amphibians. THE MODE OF LIFE HISTORY 71 There is one genus of Brachycephalidae, Rhinoderma (Fig. 25), which has attracted attention for many years because the male carries the eggs in his vocal pouch until they hatch as fully formed frogs. The tadpoles during this period have typical larval mouth parts, although these remain uncornified. The papillae about the mouth resemble more closely those of the bufonid Paludicola, as described by Fernandez (1927), than those of the brachycephalid Dendrophry- niscus stelzneri, described by the same author. No inter- mediate stages between this remarkable habit of carrying eggs in the vocal pouch and the more usual habit of laying eggs in the water are known. Many fish are "mouth breeders," that is, they carry their eggs for various periods during de- velopment in the buccal cavity, but no species of frog has this habit, although an African form was in- correctly described as doing so. The retention of larval structures in situations where they cannot function finds a parallel to Rhinoderma in other groups. The South African Arthroleptella lightfooti develops a branchial sac devoid of a spiracle, although the species undergoes its entire development on land and is unable to swim when placed in the water. Again, the African Breviceps parvus undergoes even a more direct development from egg to frog but nevertheless possesses a branchial sac within which the forelimbs develop (de Villiers, 1929). Possibly these or other larval retentions may afford a clue to the ancestry of these groups, but so little is known concerning the larvae of the Brachycephalidae that the phylo- genetic significance of the larval teeth of Rhinoderma cannot be Fig. 25.—A dissection of the vocal pouch of Rhinoderma darwinii showing several partly metamorphosed larvae. The young undergo their larval develop- ment within the vocal sac of the male. , vocal sac; , metamorphosing Please note that
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