94 SYLVAN SECEETS. 



oughly liberated, and do good service in the 

 complicated gymnastics of song production. 

 The tongue of the frog is, as a rule, attached 

 at the front of the mouth and free behind, so 

 that, in catching insects, this organ is " curled 

 over itself," and thrust out rear end foremost. 

 Curiously enough, the " singing " tree-frogs 

 are the males, the females not possessing the 

 vocal power to any great degree ; thus resem- 

 bling our oscines, whose males are the music- 

 makers. Moreover, the frog, as a fossil, dates 

 back to the time when the birds were fairly 

 beginning to separate themselves from reptile 

 life. Add to this the fact that there is a flying 

 tree-frog in Borneo, and it will be seen that 

 here is a strange, belated effort of nature to 

 urge the scaleless reptiles up to arboreal, 

 aerial, and song-singing life, by the side of 

 their more fortunate avian kinsmen, who 

 early chose a better method of develop- 

 ment! 



Turning now to rapidly sketch the really 

 wonderful vocal organs of our oscine birds, 

 I need not enter into any technical anatomi- 

 cal discussion, but, taking the mocking-bird 

 as the highest type of singer, it will be suffi- 

 cient, for the purposes of this paper, to ex- 

 plain the salient features of the song-produc- 

 ing throat in birds. First, then, all bird-song 

 is generated in a lower larynx called the 

 syrinx, a complicated little machine situated, 

 in fact, at the lower end of the trachea, 

 where it divides into two bronchial tubes, 

 and consisting in chief of an enlargement and 

 rearrangement of the compound lower ring 

 of the windpipe, a bony cross-bar, orpessulus, 

 and a membranous plate which forms a par- 

 tition between the tubes, and whose upper 

 margin is one of the vibrating vocal cords, 



