236 POPULAR SCIENCE MONTHLY. 



In considering the linguistic development of monkeys it is im- 

 portant to remember that monkeys have to a striking degree developed 

 social qualities. Detailed proof of this sociality need not be given; 

 its existence is known from the accounts of travelers, and of those who 

 have domesticated these animals, and, indeed, from observations in 

 zoological gardens. The knowledge of it is very incomplete; yet 

 enough is known to show that it is often very intimate and not without 

 complexity. Where there is such a social life, it is to be expected that 

 there will be found a development in the use of sounds. Not that 

 the presence of this development is hereby proved, but a presumption 

 is created in favor of the view that it exists.* Darwin f thought that 

 primeval man probably first used his voice in the production of true 

 musical cadences, especially during courtship; and that the imitation 

 of musical cries by articulate sounds might have given rise to words 

 expressive of various complex emotional states. Should we not rather 

 find the greater development of vocal signs in the apes earlier than 

 primeval man which had variety of vocal utterance combined with the 

 varied emotions of a complex social life, emotions not only of court- 

 ship, as Darwin supposes, but of parentage and of the various rela- 

 tions of friendliness and hostility? 



It is not meant that all the monkeys referred to have the immobile 

 ear. This is characteristic of the anthropoid apes. It is important, 

 however, to observe in very diverse species of monkeys the peculiar 

 interest in sounds; and in the anthropoid apes, which have lost the 

 mobility of the ear, there is, as we see from the accounts of the gibbon 

 and the chimpanzee, the special development of the use of, and appre- 

 ciation of, vocal and other sounds. 



It seems at first sight that the gain in the use of vocal sound made 

 by the apes is too slight to account for the change in the organ of 

 hearing. Yet we must hesitate to pronounce such a verdict when we 

 consider the immense importance of any improvement in the faculty 

 of language. Let an analogous case be considered. Mr. Fiske has 

 shown that the slow growth of the brain is a condition of the attain- 

 ment of the preeminent mental faculties possessed by man. This pro- 

 longation of infancy is in itself a disadvantage, but the gain resulting 

 from it more than counterbalances the loss. But we find a similar 

 slow growth in the case of the apes. Can we find in them any notable 

 gain in intelligence? While they are intelligent animals, we can not 

 appeal to a distinct and unchallengeable superiority. Nevertheless, 

 we believe on evolutionary principles that there is a gain in mental 

 faculty to warrant the slow maturing of their powers. Even so in the 



* Mr. Garner claims that ' the more pronounced the gregarious habits of 

 any species ' of monkey are, the higher 'the tj'pe of speech it has.' 

 t ' Descent of Man,' p. 87. 



