TREE-FROGS. 249 



dew or rain spread on the surface of the leaves is 

 rapidly absorbed into the system, and reserved to 

 supply the moisture needful for cutaneous respi- 

 ration, as already explained. In the night, they 

 are active and vociferous, and the woods in the 

 tropics then resound with the various sounds 

 emitted by these creatures. Some utter a pleas- 

 ing chirp, or clear whistle, like the voice of a 

 bird ; others produce a ringing shriek, so loud 

 and piercing as to be almost unbearable, while 

 yet others supply the bass of this nocturnal 

 concert, groaning and snoring in great variety of 

 deep, hollow, guttural sounds. These noises 

 reiterated with incessant pertinacity, through 

 the livelong night, mingled with the shrill crink- 

 ing of locusts and Cicadc^, quite banish sleep 

 from a stranger's eyes ; but habit, as in other 

 things, soon familiarises the ear to these discor- 

 dant noises, and they cease to be perceived. 

 These cries are uttered only by the males ; 

 which are furnished beneath the throat with 

 a dilatable skin, capable of being inflated into 

 a tense globose bladder, during the emission of 

 the sound. 



The prey of the HyladcE consists of Jnsects and 

 similar small creatures, which are taken by the 

 instantaneous projection of the tongue. Their 

 upper jaw is furnished with teeth like that of 

 the Frogs, but the manner in which they are 

 arranged differs in different genera. The form 

 of the tongue also varies ; in some it is forked, 

 in others it is heart-shaped, and in others it is 

 long and ribbon-like. The toes are for the most 

 part webbed, but in several genera they are free, 

 and in one they are fringed with a free membrane 



