TEOPICAL NIGHT-SOUNDS, 29 



alternation ; and between their notes, there was the differ- 

 ence of exactly a musical tone. 



Darwin speaks of the nocturnal sounds at Pdo Janeiro : 

 — " After the hotter days, it was delicious to sit quietly in 

 the garden, and watch the evening pass into night 

 Nature, in these climes, chooses her vocalists from more 

 humble performers than in Europe. A small frog of the 

 genus Hyla \i. e., of the family HyladcB, the tree-frogs 

 already alluded to], sits on a blade of grass about an inch 

 above the surface of the water, and sends forth a pleasing 

 chirp ; when several are together, they sing in harmony 

 on different notes. .... Various cicadge and crickets at 

 the same time keep up a ceaseless shrUl cry, but which, 

 softened by the distance, is not unpleasant. Every even- 

 ing, after dark, this great concert commenced ; and often 

 have I sat listening to it, until my attention has been 

 drawn away by some curious passing insect." * 



Edwards, in his very interesting voyage up the Amazon, 

 heard one night a bell-like note, which he eagerly con- 

 cluded to be the voice of the famed bell-bird. But on 



ing his Indian attendants what it was that was 

 ' gritando," he was told that it was a toad, — " everything 



,t sings by night is a toad !" 



I doubt much whether the voice first referred to in the 

 oUowing extract ought not to be referred to the same 

 (reptilian agency: — 



" During our ride home, [in Tobago,] I was startled by 

 learmg what I fully imagined was the whistle of a steam- 

 * Naturalist's Voyage, (ed. 1852,) p. 29. 



