VOCAL ORGANS. 229 



as to bring the inner surfaces into contact, a sound 

 will be produced somewhat resembling the voice of 

 the animal from which the windpipe has been taken. 

 The sound, also, will be more or less acute or grave, 

 according as the lips of the orifice approach each 

 other, and will be most intense when we blow with 

 most force. Again, when an opening is made into 

 the windpipe, either in man or other animals, below 

 the orifice, the voice is destroyed ; but will be restored 

 if the opening be mechanically stopped. M. Ma- 

 jendie says, he knows a man who has been in this 

 situation for many years, and who cannot speak 

 except when his cravat, which closes a fistulous 

 opening in the windpipe, is drawn tight. 



Although Linnaeus has' given the general character 

 of "speaking" animals to his class Mammalia^ there 

 are several, such as the ant-eaters (Myrmecophagce) 

 and the pangolins (Manes), even according to his 

 own description, altogether dumb*; while the dog 

 is said to lose its voice in the West Indies ; and 

 the same is reported of quails in Siberia t. The 

 greater or less perfection of the voice seems, in- 

 deed, to depend upon the degree of perfection with 

 which the orifice of the windpipe is formed in the 

 classes of animals possessing that organ ; and it is 

 by the varying number of membranes or muscles 

 in its general structure, or by variations in their 

 shape, position, or elasticity that quadrupeds and 

 most other animals are rendered capable of making 

 those peculiar sounds by which their different kinds 

 are respectively characterized, and are enabled to 

 neigh, bray, bark, or roar ; to purr, as the cat and 

 the tiger ; to bleat, as the sheep ; and to croak, as 

 the frog. The frog, however, has a sack or bag of 



* System a Naturae, in loco, 

 t Pennant, Arct. Zool. ii. 320. 



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