MENTAL POWERS. 85 



probable that the imitation of musical cries by articulate sounds 

 may have given rise to words expressive of various complex 

 emotions. The strong tendency in our nearest allies, the monkeys, 

 in microcephalous idiots,™ and in the barbarous races of mankind, 

 to imitate whatever they hear deserves notice, as bearing on the 

 subject of imitation. Since monkeys certainly understand much 

 that is said to them by man, and when wild, utter signal-cries of 

 danger to their fellows;" and since fowls give distinct warnings 

 for danger on the ground, or in the sky from hawks, (both, as 

 well as a third cry, intelligible to dogs)," may not some unusually 

 wise ape-like animal have imitated the growl of a beast of prey, 

 and thus told his fellow-monkeys the nature of the expected 

 danger? This would have been a first step in the formation of a 

 language. 



As the voice was used more and more, the vocal organs would 

 have been strengthened and perfected through the principle of 

 the inherited effects of use; and this would have reacted on the 

 power of speech. But the relation between the continued use of 

 language and the development of the brain, has no doubt been 

 far more important. The mental powers in some early progenitor 

 of man must have been more highly developed than in any existing 

 ape, before even the most imperfect form of speech could have 

 come into use; but we may confidently believe that the con- 

 tinued use and advancement of this power would have reacted 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 re- 

 quires, 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 inove- 

 ments of dogs during their dreams. We have, also, seen that ani- 

 mals 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 



1^ Vog-t, 'Memoire sur les Microcephales,' 1867, p. 169. With respect to 

 savages, I have given some facts in my 'Journal of Researches,' &c., 

 1845, p. 206. 



" See clear evidence on this head in the two works so often quoted, 

 by Brehm and Rengger. 



^ Houzeau gives a very curious account of his observations on this 

 subject in his 'Facultes Mentales des Animaux," tom. ii., p. 348. 



5» See remaj-ks on this head by Dr. Maudsley, 'The Physiology and 

 Pathology of Mind,' 2nd edit. 1868, p. 199. 

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