Page:Popular Science Monthly Volume 59.djvu/81

Rh existence that it is doubtful if they need to fall off into the water; at all events, some tadpoles of Hyla nebulosa taken out of this nest and put into water, died in a few hours from lack of breath, being unable to live without the peculiar air supply they were used to. However, the larvae of another frog (Phyllomedusa hypochondrialis) are set loose from the nest when the rain softens it and do fall into the water to continue their tadpole life. This species occurs in Paraguay, and makes use of the leaves of trees near the water. The male rides on the back of the female, while both bend in the edges of a single leaf till it makes a funnel. In this the eggs are laid and fertilized. The jelly surrounding them holds the leaf in place till the tadpoles hatch and are ready for the rain to forward them to their new destination.

In Japan there is also a nest-making frog (Rhacoporus Schlegeli) which is said to lay its eggs sometimes amongst leaves on bushes or trees. However, its usual habit is to make a nest in the ground as indicated in Fig. 3. Awakening from their winter sleep, the frogs crawl along the edges of rice fields and swamps and dig out holes above the water level. The female carries the much smaller male, and both become buried in a hole 6-9 cm. wide and 10-15 cm. above the surface of the water. This nest cavity is smoothed inside by the movements of the female and is then, in the night, supplied with a ball of white matter full of air-bubbles. This is tough and elastic and 6-7 cm. thick. This mass is to supply moisture and air for the young. It emerges from the cloaca along with the eggs, and is then kneaded thoroughly by remarkable movements of the feet of the female.