LARYNX OF THE LOWER ANIMALS. 1S3 



ticulate sounds. I had always supposed that they were 

 destitute of some parts of the vocal organs. 



Dr. B. All we can say about the matter is, that the 

 functions of voice is not needed by them, and therefore 

 they are not provided with it, they can gratify all their 

 natural wants, and fulfil the purposes of their being per- 

 fectly well without it. 



In some of the apes, the vocal organs have a curious 

 structure. There is connected with the larynx a bony, 

 or a membranous sac, either single and placed in the 

 middle of the neck*, or as in some species double, one 

 on each side extending the whole length of the neck. 

 From these sacs there is always a free communication 

 with the cavity of the larynx. 



Emily. May not the inability of uttering sounds in 

 these creatures, be attributed to this arrangement ? Or 

 is it, after all, solely the result of moral causes ? 



Dr. B. When this peculiarity of structure was first 

 brought to light, philosophers thought that they had 

 found out for certain, the true reason why apes do not 

 speak, but further researches proved that there exists 

 many species of apes in which this peculiarity is not 

 found ; and yet they are just as destitute of the art of 

 speech as the others. 



Emily. How does this arrangement effect the pro- 

 duction of sounds in these animals ? 



Dr. B. The voice of those with the bony box, is 

 exceedingly intense and disagreeable. The Alouatte 

 and Ouaririe, two species in South America, have long 

 attracted the attention of travellers by the intensity and 

 harshness of their cries, and hence have received the 

 name of Howlers. " Their cry, or rather horrible rat- 

 tling screams which they make, may well inspire terror, 

 and seems as if the forests contained the united howlirigs 

 of all its savage inhabitants together." 



In the larynx of the dog, sheep, cat, ox, &c. we find 

 the same number of parts, and the same arrangement, as 

 in man, the principal difference being in the width and 



