HVLIDAE 



197 



spot where the Tree-frog sits, the sound ceases. But keep quiet, 

 and it will be resumed after a few moments. You will discover 

 the frog on a grass-stem, on a leaf of a low branch, or in the 

 mud. Seize it quickly, for it is a most wonderful jumper, and it 

 will utter a loud and shrill, most startling cry, somewhat similar 

 to that of a wounded cat." 



The " Smith " makes very regular pools, in the shallow 

 water of ponds, or nurseries for the tadpoles surrounded by a cir- 

 cular wall of mud. Dr. Goeldi has watched the building process 

 during a moonlit night : " We 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 builder's head and front 

 part of body appeared suddenly with a load of mud on some 

 opposite point. But what astonished us in the highest degree 

 was the manner in which it used its hands for smoothing the 

 inside of the mud wall, as would a mason with his trowel. 

 When the height of the wall reached about 4 inches, the frog 

 was obliged to get out of the water. The parapet of the wall 

 receives the same careful smoothing, but the outside is neglected. 

 The levelling of the bottom is obtained by the action of the lower 

 surface (belly and throat principally) together with that of the 

 hands." 



The male takes no active share in the construction of the 

 nest, but wiU suddenly climb up the wall of his home, and then 

 upon the back of his busy mate. The building operation may 

 take one or two nights, and is performed in the most absolute 

 silence ; the croakers around are all males clamouring for a 

 mate. 



The eggs are laid during one of the following nights, and are 

 hatched some four or five days later, the parents keeping hidden 

 in the neighbourhood of the nursery. Heavy rains may destroy 

 the walls, and thus prematurely release the tadpoles. 



It is only owing to such keen observers and lovers of 

 nature's fascinating ways that the breeding habits of some 

 Brazilian Hylidae have become known. 



H. nebulosa, s. luteola also living in Brazil, is yellow above, 

 with brown dots ; the sides of the belly and thighs have trans- 



