S8 The Descent of Man. Pabt L 



any existing ape, before even the most imperfect form of spee'"'*. 

 could have come into use ; out we may confidently believe that 

 the continued use and advancement of this power vpould have 

 reaf-ted on the mind itself, by enabling and encouraging it to 

 carry on long trains of thought. A complex train of thought 

 can no more be carried on without the aid of words, whether 

 spoken or silent, than a long calculation without the use of 

 figures or algebra. It appears, also, that even an ordinary train 

 of thought almost requires, or is greatly facilitated by some 

 form of language, for the dumb, deaf, and blind girl, Laura 

 Bridgman, was observed to use her fingers whilst dreaming." 

 Nevertheless, a long succession of vivid and connected ideas may 

 pass through the mind without the aid of any form of language, 

 as we may infer from the movements of dogs during their 

 dreams. We have, also, seen that animals are able to reason 

 to a certain extent, manifestly without the aid of language. 

 The intimate connection between the brain, as it is now 

 developed in us, and the faculty of speech, is well shewn by 

 those curious cases of brain-disease in which speech is specially 

 affected, as when the power to remember substantives is lost, 

 whilst other words can be correctly used, or where substantives 

 of a certain class, or all except the initial letters of substantiven 

 and proper names are forgotten.™ There is no more improb- 

 ability in the continued use of the mental and vocal organs 

 leading to inherited changes in their structure and functions, 

 than in the case of handwriting, which depends partly on the 

 form of the hand and partly on the disposition of the mind ; and 

 hand-writing is certainly inherited.'" 



Several writers, more especially Prof. Max Miiller,*^ have 

 lately insisted that the use of language implies the power of 

 forming general concepts ; and that as no animals are supposed 

 to possess this power, an impossible barrier is formed between 

 them and man."* With respect to animals, I have already 



'° See remarks on this head by '- Lectures on ' Mr. Darwin's Phi- 



Dr. Maudsley, 'The Physiology and losophy of Language,' 1873. 



Pathology of Mind,' 2ad edit. 1868, "= The judgment of a distin- 



p. 3 99. guished philologist, such as Prof. 



o" Many curious cases have been Whitney, will have far more weight 



recorded. See, for instance, Dr. on this point than anything that 



Bateman ' On Aphasia,' 1870, p. 27, I can say. He remarks (' Oriental 



3L, 53, 100, &o. Also, 'Inquiries and Linguistic Studies,' 1873, p. 



Concerning the Intellectual Powers,' 297), in speaking of Bleek's views : 



by Dr. Abercrombie, 1838, p. 150. " Because on the grand scale lan- 



81 'Irje Variation of An'mals " gnage is the necessary au.xiliary 



and Planrs under Dora»;tica'ion,' " of- thought, indispensable to t}ie 



rol. ii, p 6. ■' development of tl:e powtr o/ 



