Title: The biology of the amphibia
Identifier: biologyofamphibi00nobl (find matches)
Year: 1931 (1930s)
Authors: Noble, Gladwyn Kingsley, 1894-1940
Subjects: Amphibians
Publisher: New York : McGraw-Hill
Contributing Library: ASC - York University Libraries
Digitizing Sponsor: York University - University of Toronto Libraries

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SEX AND SECONDARY SEX CHARACTERS 117 in relation to the apparent phylogenies of the various species. Although the more familiar frogs and toads have the prepollex region of the male covered with a nuptial pad, the prepollex itself or the adjacent digits may be modified into a spine or "dagger" in other species. In Petropedetes newtoni the metacarpus of the first digit is enlarged, spikelike, and protrudes through the skin
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Fig. 41.—Closely related frogs frequently have markedly different secondary sexual characters. The forelimb of the male Hoplophryne uluguruensis (A) compared with the forelimb of H. rogersi (B), seen from the same ventral aspect. as an effective instrument for holding the female (Fig. 40C). In Telmatobius jelskii the same element is enlarged, in Dis- coglossus it is broadened, while in Leptodactylus ocellatus it is bifid with two spines. In other frogs it is the prepollex which is hypertrophied to form a recurved spine. There is no 'evidence of a progressive enlargement of this spine in any Salientia. For example, in the recently described "Banana Frogs" of East Africa, a pad of sharp dermal spines occurs on each side of the chest in the male Hoplophryne uluguruensis and another cluster of large dermal spines over the prepollex region of each hand (Fig. 41 A). Such a formidable array of spines rarely occurs in

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