In undergoing this change, it is chiefly the organs of respiration that manifest alteration. In its earliest form the young batrachian, living in the water, breathes as a fish does by gills, either free and projecting as in the water-newt, or partially covered by integument as in the tadpole. But the gills disappear as the lungs gradually become developed: the duration of the process being on an average one hundred days from the time the eggs were first deposited. After this important change, the true batrachian is incapable any longer of living continuously in water, and either betakes itself altogether to the land, or seeks the surface from time to time to replenish its exhausted lungs.[3201]

The change in the digestive functions during metamorphosis is scarcely less extraordinary; frogs, for example, which feed on animal substances at maturity, subsist entirely upon vegetable when in the condition of larvæ, and the subsidiary organs undergo remarkable development, the intestinal canal in the earlier stage being five times its length in the later one.

Of the family of tailed batrachians, Ceylon does not furnish a single example; but of those without this appendage, the island, as above remarked, affords many varieties; seven distinguishable species pertaining to the genus rana, or true frogs with webs to the hind feet; two to the genus bufo, or true toads, and five to the Polypedates, or East Indian "tree-frogs;" besides a few others in allied genera. The "tree-frog," whose toes are terminated by rounded discs which assist it in climbing, possesses, in a high degree, the faculty of changing its hues; and one as green as a leaf to-day, will be found grey and spotted like the bark to-morrow. One of these beautiful little creatures, which had seated itself on the gilt pillar of a lamp on my dinner-table, became in a few minutes scarcely distinguishable in colour from the or-molu ornament to which it clung.

List of Ceylon Reptiles.

I am indebted to Dr. Gray and Dr. Günther, of the British Museum, for a list of the reptiles of Ceylon; but many of those new to Europeans have been carefully described by the late Dr. Kelaart in his Prodromus Faunæ Zeylanicæ and its appendices, as well as in the 13th vol. Magaz. Nat. Hist. (1854).

SAURA.

OPHIDIA.