. Zoology for high schools and colleges. Zoology. SUPPBESSED METAMORPHOSIS. 485 As an example of a suppressed metamorphosia, due ap- parently to a radical difference in the physical environment of the animal, may be cited the case of a tree-toad in the island of Guadaloupe. There are no marshes on this island, consequently in a species of Hylodes the development of the young is direct; they hatch from the eggs which are laid under moist leaves, without tails, and are otherwise, ex- cept in size, like the adults. On the other hand, a tree-toad of the island of Martinique {Hylodes Martinicensis,
. Zoology for high schools and colleges. Zoology. SUPPBESSED METAMORPHOSIS. 485 As an example of a suppressed metamorphosia, due ap- parently to a radical difference in the physical environment of the animal, may be cited the case of a tree-toad in the island of Guadaloupe. There are no marshes on this island, consequently in a species of Hylodes the development of the young is direct; they hatch from the eggs which are laid under moist leaves, without tails, and are otherwise, ex- cept in size, like the adults. On the other hand, a tree-toad of the island of Martinique {Hylodes Martinicensis, Fig. 436) has tadpoles, which it carries on its back. The female of Nototrema marsupiatum Dumeril and Bibron, of the Andes, has a marsupium or sac on its back in which the young are carried. The Notoddphys of South America has similar habits ; for example, the female Opi&tliodel- phys {Notodelpiliyis) ovifera has a dor- sal sac a centimetre deep in which the eggs are carried. In the young of this and of Gastrotlieca also of Central America, Peters found traces of external gills. Tlie Pipa, or Suri- nam toad {Pipa Americana Laurent), which has no tongue, neither teeth in the upper Jaw, has similar breeding Y\g. Martinique habits. In this interesting toad the ^^T^ back?""'""^ ""^ ^°â¢^ young, according to Prof. "Wyman, are provided with small gills, which, however, are of no use to them, as the tadpoles do not enter the water, but are carried about in cavities on the back. The eggs are placed by the male on the back of the female, where they are fertilized. The female then enters the water; the skin thickens, rises up around each egg and forms a marsupial sac or cell. The young pass through their metamorphosis in the sacs, having tails and rudimentary gills ; these are absorbed before they leave their cells, the limbs develop, and the young pass out in the form of the adult. The toad {Bufo lentiginosus Shaw) is exceedingly use
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