are enabled
to lay only about a dozen to fifteen eggs at a time, instead of the
countless hundreds often produced by many of their relations.

Tree-frogs have, of course, in most circumstances much greater
difficulty in getting at water than pond-frogs; and this is especially
true in certain tropical or desert districts. Hence most of the frogs
which inhabit such regions have had to find out or invent some
ingenious plan for passing through the tadpole stage with a minimum of
moisture. The devices they have hit upon are very curious. Some of
them make use of the little pools collected at the bases of huge
tropical leaf-stalks, like those of the banana plant; others dispense
with the aid of water altogether, and glue their new-laid eggs to
their own backs, where the fry pass through the tadpole stage with the
slimy mucus which surrounds them. Nature always discovers such cunning
schemes to get over apparent difficulties in her way: and the
tree-frogs have solved the problem for themselves in half a dozen
manners in different localities. Oddest of all, perhaps, is the dodge
invented by "Darwin's frog," a Chilean species, in which the male
swallows the eggs as soon as laid, and gulps them into the
throat-pouch beneath his capacious neck: there they hatch out and pass
through their tadpole stage: and when at last they arrive at frogly
maturity, they escape into the world through the mouth of their
father.

[Illustration: NO. 8. THE SURINAM TOAD.]

The Surinam toad, represented in No. 8, is also the possessor of one
of the strangest nurseries known to science. It lives in the dense
tropical forests of Guiana and Brazil, and is a true water-haunter.
But at the breeding season the female undergoes a curious change of
integument. The skin on her back grows pulpy, soft, and jelly-like.
She lays her eggs in the water: but as soon as she has laid them, her
lord and master plasters them on to her impressionable back with his
feet, so as to secure them from all assaults of enemies. Every egg is
pressed separately into a bed of the soft skin, which soon closes over
it automatically, thus burying each in a little cell or niche, where
it undergoes its further development. The tadpoles pass through their
larval stage within the cell, and then hop out, in the four-legged
condition. As soon as they have gone off to shift for themselves, the
mother toad finds herself with a ragged and honeycombed skin, which
must be very uncomfortable