. The biology of the amphibia. Amphibians. THE INTEGUMENT 135 glands of Salamandra air a differs from that of S. salamandra and is called "; These alkaloids have the same effect as the natural poison. Toad skins are used as medicine by the Chinese, and their therapeutic value may not be wholly psychological. Abel and Macht discovered adrenalin in the paratoid glands of the toad. Apparently adrenalin was not secreted as such by the gland, but resulted from a chemical change within the mature secretion (Shipley and Wislocki; 1915). It is, never- theless, remarkable to find
. The biology of the amphibia. Amphibians. THE INTEGUMENT 135 glands of Salamandra air a differs from that of S. salamandra and is called "; These alkaloids have the same effect as the natural poison. Toad skins are used as medicine by the Chinese, and their therapeutic value may not be wholly psychological. Abel and Macht discovered adrenalin in the paratoid glands of the toad. Apparently adrenalin was not secreted as such by the gland, but resulted from a chemical change within the mature secretion (Shipley and Wislocki; 1915). It is, never- theless, remarkable to find adrenalin in an external secretion. Species differ enormously in the virulence of their poison. It has been noted (Wright, 1914) that the common Pickerel Frog, R. palustris, will frequently^kill other species of fro^Samed home in the sam^ar^rn it. Many of th^, Vic^^rightly colored ^$peci^ especially those^^arJJ&& with yellow and red, ^iave been found to be highly poisonous, but bright colors are not always linked with virulent secre- tions. Brazil and Vellard (1926) found that the dull- colored Ceratophrys americana has a virulent poison, while the gaudy C. dorsata has innocuous skin secretions. The large Leptodactylus pentadactylus has bright thighs, but it lacks the highly poisonous secretions of the drab-colored Bufo marinus. The latter species produces one of the most virulent poisons known among the Amphibia, one that frequently kills dogs which have not learned to leave the toad alone. Whether or not because of this poison, the Marine Toad is almost ubiqui- tous in the American tropics. Some species of the neotropical brachycephalid toad, Dendro- bates, are bright green or pink, spotted with a dark tone. Their secretions are used by Indians of Colombia as a source of poison for their arrows. Whether these species are more poisonous than. Fr. Ep. Fig. 50.—Diagram of a longi- tudinal section of the toe of a tree frog, showing the tree-climbing mechanism. , f
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Keywords: ., bookcentury1900, bookpublishernewyorkmcgr, booksubjectamphibians
