532 TEE POPULAR SCIENCE MONTHLY 



INSTINCT AND INTELLIGENCE IN BIEDS.— I 



By Professor FRANCIS H. HERRICK 



WESTERN RESERVE UNIVERSITY 



THEEE is no doubt, as Jevons has remarked, that if ants had better 

 brains than men, they would either destroy the human race or 

 reduce it to a state of slavery, but these busy little workers offer no 

 black or yellow peril to mankind, for they are all headed in the wrong 

 direction. In the social hymenoptera nature seems to have done her 

 best with a nervous system built upon the simple arthropod plan, in 

 which segmentation, begun at a still lower level in the animal scale, is 

 the dominant character of its structure, and instinct the ruling method 

 of its response. 



The vertebrate, on the other hand, has a nervous system of not only 

 a higher but of a very different order, in which response has left the 

 beaten track of instinct, and become more and more molded upon 

 experience. Classification of these higher types on the ground of 

 anatomy agrees plainly with classification on the score of behavior, and 

 this agreement is based upon the structure of the nervous system, the 

 chief function of which is to order and control response. 



It is to the evolution of the cerebrum that the vertebrate owes its 

 powers of rational response, and the higher we rise in the scale of verte- 

 brate ascent from the bony fishes, the greater the development of the 

 cerebral cortex, and the keener the mind of the animal, or the greater 

 its power to subdue its hereditary tendencies, to make its acts accord 

 with the results of experience, or the needs of the moment, and to 

 anticipate the future. 



The instincts used to be regarded as immutable, and are now often 

 spoken of as " stereotyped," but in the use of the latter term there is 

 need of frequent qualification, and habits even by repetition become 

 automatic. The mechanical operation of habits, which is universally 

 recognized, has given rise to the idea that acquired automatism may ap- 

 pear in the descendants as inherited or congenital automatism, that in- 

 stincts are inherited habits and merely illustrate " lapsed intelligence," 

 or habits from which the intellectual processes through which they were 

 originally acquired have " lapsed " or disappeared. The confusion and 

 absurdity with which this view can invest a difficult question is well 

 illustrated by Eimer's 1 attempt to explain the parasitic instinct of the 

 European cuckoo, which regularly lays its eggs in other birds' nests. 



tinier, Theodor G. H., "Organic Evolution," p. 256, London, 1890. 



