282 FROGS AND TOADS. 



first saw some slight movement in the water, produced by something stirring 

 below the surface. We then soon saw a mass of mud rising to the surface, carried 

 by a tree-frog, of which no more than the two hands emerged. Diving again, after 

 a moment's time, the frog brought up a second mass of mud, near the first. This 

 was repeated many times, the result being the gradual erection of a circular wall. 

 From time to time the head and front part of the body of the builder appeared 

 suddenly with a load of mud at some point ; but what astonished us in the highest 

 degree was the manner in which the frog used its hands for smoothing the mud- 

 wall, as would a mason with his trowel. And by examining the hands of this, 

 hyla, it will readily be understood how they are most serviceable trowels, their 

 terminal joints bearing large expansions. This careful process of smoothing could 

 be better observed as the wall gradually heightened, until it reached about four 

 inches, when the frog was compelled to come out of the water. The parapet of 

 the wall receives the most careful smoothening, the outside being neglected, and 

 the levelling of the bottom attained by the action of the lower surface of the 

 creature's body, aided by the hands. The aspect of the pool may be compared to- 

 the crater of a volcano, or a vessel of a foot in diameter filled with water. Although 

 the female undertakes the entire task of building, she is incommoded the whole 

 time by the male sitting on her back. Should he be frightened from his post, he 

 will soon emerge from the water at a distance of a few feet, when, if signs of 

 danger be wanting, he will climb the walls of the nest and regain his original seat." 



Another Brazilian tree-frog of the same genus (H. goeldii) breeds in the 

 water contained in the central cup of certain trees belonging to the Bromeliacece. 

 Dr. Goeldi states that the first specimen found was a female, carrying on her 

 back a large globular mass of whitish eggs. When put in a vivarium, "for a 

 few days the egg-mass remained attached to the mother's back. But suddenly 

 it fell away, and simultaneously I saw in the glass some small, nearly black 

 coloured frogs, all provided with the anterior and posterior legs, together with 

 a larval tail of medium or rather snmll size." 



Yet another tree-frog from Brazil (H. nebulosa) has acquired the remarkable 

 habit of depositing its eggs in the sheaths of old and decaying leaves of bananas. 

 The writer from whom we have been quoting states that this frog " glues its lumps 

 of eggs on the edges and on the inside of banana leaves, where, even during the 

 hot hours of the day, sufficient coolness and moisture are preserved. These lumps 

 are enclosed in a frothy, whitish substance, comparable to the scum formed by 

 certain Cicadidce. Sometimes the tailed larves are seen struggling in this frothy 

 mass. If put into fresh water, all will die in a few hours." 

 Pouched Tree- On account of the peculiarity of their reproduction, mention 



Frogs. mu st b e mac i e O f the curious pouched tree-frogs (Nototrema), dis- 

 tinguished from the typical genus by the presence of a backwardly-opening pouch 

 at the hinder-end of the back in the females. These frogs are represented by some 

 half-dozen species, mainly confined to Central and Western Tropical America, 

 although one of their number is found on the eastern side of that continent at- 

 Pernambuco. The pouch of the female is extended beneath the skin of the back 

 and sides to form a very large chamber, in which the eggs and tadpoles undergo 

 the whole of their transformations. The eggs, generally fifteen or sixteen in 



