692 THE AMERICAN NATURALIST. (VoL. XXXIV. 
The adult of the Brazilian frog, Cystizgnathus mystaceus, in 
the province of Rio Grande do Sul, never goes to water, even 
to spawn. In the breeding season it prepares a hole under a 
stone or decayed wood, near the edge of a pool, but above the 
water line; here the eggs are deposited in comparatively small 
numbers. The frothy substance about them probably serves 
as food for the tadpoles, since it diminishes in quantity as 
they grow. In a dry season the tadpoles may attain great 
size in the nest, but ordinarily they are washed into the pool, 
when, after a rain, it overflows. They probably do not go 
through the entire metamorphosis in the nest, however long 
they may be detained in it, for tadpoles that had grown there 
to a considerable size still possessed tails. During develop- 
ment in the nest, external gills were observed; the tail was 
thought to be not so powerful as that of Rana esculenta, and 
is at first light in color, like the egg, but later becomes pig- 
mented dorsally. Another Brazilian nest builder is Hy/a faber, 
which is common in Rio de Janeiro, especially in the mountain 
regions. The female constructs for the eggs a shallow vessel 
of mud, about four inches high and a foot in diameter. The 
nest is carefully built on the bottom of a pool, with its edge 
projecting above the water. Similar nests have been found in 
Rio Grande do Sul! and there it has been observed that, if the 
pool dries, the tadpoles in their little lagoons perish, while the 
young of Cystignathus mystaceus survive, huddled together in 
the frothy substance in their nest in the bank. The eggs of 
Cystignathus typhonius, a frog common in Porto Rico, have 
been found under conditions similar to those described in the 
case of C. mystaceus. The tadpoles swam when put into water. 
The appearance of the hind legs and of the fore legs and the 
disappearance of the tail were observed. 
In Ceylon, a green frothy spawn, about the size of 
egg, has been found sticking to the walls of cisterns, to per- 
pendicular rocks of quarries over water, and to the damp 
a crow's 
o Grande do Sul that such 
ut there is good reason tO 
rog has been 
1 It was formerly supposed by the observer in Ri 
nests were constructed by Cystignathus ocellatus, b 
suppose that Z/y/a faber is the artisan. In Rio de Janeiro this f 
observed in the very act of building, which takes place at night. 
