87 



injury amid the general destruction caused by the lesions de- 

 scribed. I cannot dismiss this hypothesis without calling atten- 

 tion to the confirmation that would be given to Mr. Darwin's 

 views if M. Broca's theory were correct^ and this particular 

 • fold could be shown to be the seat of speech in man. And here 

 I must call attention to the comparison which Carl Vogt makes 

 between our quadrumanous cousins and ourselves. According 

 to this distinguished naturalist^ the apes have an extremely 

 imperfect development of the third frontal convolution, and the 

 same condition exists in the microcephali ; therefore,, he says, as 

 neither apes nor microcephali can speak. Comparative Anatomy 

 gives a subsidiary support to the theory wliich places speech in 

 this convolution. 



I have been in communication with Professor Vogt in refer- 

 ence to this subject, and he has kindly favoured me with his 

 views, which I consider so extremely pertinent to our subject, 

 that I shall give them in his own words, as contained in an 

 autograph letter to myself. 



The brain of man and that of apes, especially of the anthropoid apes 

 (orang, chimpanzee, gorilla), are constructed absolutely upon the same type — 

 a type by itself, and which is characterized, amongst other thmgs, by the 

 fissure of Sylvius, and by the manner in -svliich the island of Keil is formed 

 and covered ; thus in man, the third frontal convolution is extraordinarily 

 developed, and covers partly the insula, whilst the transverse central convo- 

 lutions are of much less importance. In the ape, on the other hand, the 

 third frontal convolution is but slightly developed, whilst the central trans- 

 verse convolutions are very large. 



To show the bearing all this has upon the seat of speech, I would refer 

 to the microcephali, who do not speak ; they learn to repeat certain words 

 like parrots, but they have no articulate language. Now, the microcephali 

 have the same conformation of the third frontal convolution as apes ; they 

 are apes as far as the anterior portion of their brain is concerned. Thus, 

 man speaks ; apes and microcephali do not speak. Certain observations 

 have been recorded which seem to place language in the part which is 

 developed in man, and contracted in the microcephali and the ape ; Com- 

 parative Anatomy, therefore, comes in aid of M. Broca's doctrine. 



I have reason to believe that these views of Professor Vogt 

 qre not very generally known in this country; and I need 

 hardly allude to the extremely important bearing they have 

 upon, the question at issue; for if Professor Broca's theory could 

 be proved to be correct, — that this third frontal convolution is 

 the seat of human speech,— a strong argument could be adduced 

 in favour of Darwinism. It might be said the ape possessed the 

 rudiments of speech in an undeveloped form, and that in subse- 



