nt 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.[1]

[Footnote 1: A few Batrachians, such as the _Siren_ of Carolina, the
_Proteus_ of Illyria, the _Axolotl_ of Mexico, and the _Menobranchus_ of
the North American Lakes, retain their gills during life; but although
provided with lungs in mature age, they are not capable of living out of
the water. Such batrachians form an intermediate link between reptiles
and fishes.]

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
larvae, 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. Guenther, 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 Fauna
Zeylanicae_ and its appendices, as well as in the 13th vol. _Magaz. Nat.
Hist._ (1854).

SAURA.

Hydrosaur