EVOLUTIONARY SIGNIFICANCE OF HUMAN CIIxVRACTER. 385 



untold ages they involved nothing more than the discovery and 

 application of general principles of the simplest kind ; such as the 

 customary sequence of natural phenomena, and the anticipation 

 of their operations, as, for instance, in the laying up of winter 

 provisions. Occasionally deductive application of an old rule to a 

 new case would arise, as in that of the Mygale spider which was 

 observed by Dr. McCook to substitute cotton for her own silk for 

 the lining of her nest. The development of the rational faculty 

 has been rather in quantity and quality, than in the nature of its 

 constituent parts. I may remark, however, that the embryological 

 order is here again different from the paleontological. Inherited 

 aptitudes, as for music, calculation, etc., precede, in children, any 

 considerable powers of thought, while the order of development of 

 the race has been the reverse. 



As regards the appearance of the qualities of mind already 

 mentioned, which depend on character of tissue, it is difficult to 

 present an order which shall be generally true. Our ignorance 

 of the subject is profound ; nevertheless observation of animals 

 and men leads to the following conclusions : First, the primitive 

 mind is negative, unimpressible, and little sensitive. In evolution, 

 sensibility has been developed under stimuli, and diminished by 

 disuse and repose. The energy of high-strung sensibility has prob- 

 ably ever won for its possessors success in the struggle for existence, 

 and more or less immunity from the pains which stimulate to ac 

 tion.* It is true that the non-aggressive and ever-harassed Her- 

 bivora have developed the higher brain structure. The inferiority 

 of brain type of the Carnivora is a well-known fact of present and 

 past time. The early ruminants were smaller than the contempo- 

 rary flesh-eaters, and therefore subject to the greatest risks. The 

 best-developed brains, those of the Quadrumana, have been devel- 

 oped in still more defenseless animals, who in their arboreal life 

 have been confronted by still more complex conditions.! 



Impressibility or sensitiveness has evidently been the means of 

 acquisition of some of the other qualities mentioned. Thus inten- 

 sity may have resulted from active use accompanied by vigorous 

 nutrition, and the consequent construction of compact force-con- 

 verting tissue. Rapidity without intensity must also result from 



* " The Relation of Man to the Tertiary Mammalia," "Penn Monthly," 1875. 



f Mr. C. Morris very reasonably regards the social life of these animals as the 



source of their development of intelligence. See "American Naturalist," June, 



1886. (Ed. 1886.) 

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