Human Infancy and the Recapitulation Theory 67 



Lankester regards the conclusions of Marsh as illustrating a 

 general truth, to which the case of Homo and his pithecoid rela- 

 tions is no exception. This authority further considers this 

 progression to be one from action based on instinct to action 

 based on " educability. " Educability is transmitted by heredity 

 but its products are not. Instinct and educability are to a large 

 extent in opposition, the loss of the first making an opportunity 

 for the appearance of the latter. Lewis and Romanes are funda- 

 mentally wrong in imputing instinct to " lapsed intelligence. " 

 There is no community between the two. One can grow only 

 as the other diminishes. 7 



In a study of the causes of extinction of mammalia, Osborn 

 assigns to brain capacity, among a variety of causes, a primary 

 importance. The identification of educability with brain size 

 in surviving mammal forms appears clearly in the following: 



" . . . the chief advantages of brain capacity are un- 

 doubtedly in relation to adaptability of habit, resourcefulness in 

 times of exposure, alertness in avoiding new dangers to which 

 the young may be exposed, enterprise in seeking new habitat 



." 8 



The early insistence upon the cruelty of the natural order as 

 described by Darwinism, and especially the conflict between the 

 state of nature and that of art and humanity, so vigorously 

 urged by Huxley in his "Evolution and Ethics," brought out a 

 series of replies calling attention to the facts of parental care and 

 mutual aid among animals and men. These facts had been 

 alluded to by naturalists incidentally but were made the principal 

 theme of two very widely read authors. These were Henry 

 Drummond in the ''Ascent of Man" (1894) and P. Kropotkin 

 in a series of articles 9 in which the facts illustrative of co-opera- 

 tion among animal and savage societies were brought together. 



In 1898, Sutherland, in the early chapters of the "Origin and 

 Growth of the Moral Instinct," summarized the facts of parental 

 care among the principal vertebrate groups in terms indicative 

 of its historical evolution. The high fertility, rapid hatching, 

 and early maturity by means of which the species of the lower 

 groups were maintained is shown to yield to the biologically 



Nature, Vol. LXI, 1900, p. 624. 



Amer. Naturalist, Vol. XL, 1906, p. 857. 



Reprinted in Mutual Aid as a Factor in Evolution, 1902. 



