58 MENTAL EVOLUTION IN MAN. 



In this connection also I may state that, with the assistance 

 of the keeper, I have succeeded in teaching the Chimpanzee 

 now at the Zoological Gardens to count correctly as far as 

 five. The method adopted is to ask her for one straw, two 

 straws, three straws, four straws, or five straws — of course 

 without observing any order in the succession of such requests. 

 If more than one straw is asked for, the ape has been taught 

 to hold the others in her mouth until the sum is completed, 

 so that she may deliver all the straws simultaneously. For 

 instance, if she is asked for four straws, she successively 

 picks up three straws and puts them in her mouth : then she 

 picks up the fourth, and hands over all the four together. 

 This method prevents any possible error arising from her 

 interpretation of vocal tones, which might well arise if each 

 straw were asked for separately. Thus there can be no doubt 

 that the animal is able to distinguish receptually between the 

 numbers i, 2, 3, 4, 5, and understands the name for each. 

 Further than this I have not attempted to take her. I 

 may add that her performance has been witnessed by the 

 officers of the Zoological Society and akso by other naturalists, 

 who will be satisfied with the accuracy of the above account. 

 But the ape is capricious, and, unless she happens to be 

 in a favourable mood at the time, visitors must not be dis- 

 appointed if they fail to be entertained by an exhibition of 

 her learning. 



The great physiologist Miiller and the great philosopher 

 Hegel are quoted by Mr. Mivart as maintaining, that " to 

 form abstract conceptions of such operations as of something 

 common to many under the notion of cause and effect, is a 

 perfect impossibility to them " (animals *) ; and no doubt 

 many other illustrious names might be quoted in support of 

 the same statement But it seems to me that needless 



taneously estimated with accuracy. [^Sitziings berichten der Gesellschaft fiir 

 Mcdicin und Nalut-vissenshaft, 29 Juli, 1 88 1.) The number admits of being 

 largely increased by practice, until, with an exposure to view of one second's 

 duration, the estimate admits of being correctly made up to between twenty and 

 thirty objects. (See also Mental Evolution in Animals^ p. 138.) 

 * Lessons from N^ature, pp. 219, 220. 



