NATIONAL ACADEMY BIOGRAPHICAL MEMOIRS — VOL. VII 



years of his life, one of them entitled "Heredity and varia- 

 tion, logical and biological" (1906) and the other his address 

 before the Seventh International Zoological Congress in 1907, 

 entitled "Are heredity and variation facts?" he concludes that 

 these terms "represent only imperfect mental concepts, and not 

 facts, and that neither heredity, nor variation nor species can 

 reside in germ cells, nor in chromatin, nor in gemmules. The 

 gradual disappearance of attempts to invent evolutionary hy- 

 potheses to account for individual development or ontogeny, 

 and the return to a more epigenetic standpoint . . . seems 

 to me a notable reformation. Ancestral development is as 

 epigenetic as individual development. The being of an indi- 

 vidual is not in itself, but in reciprocal interrelations between 

 it and its environment. If these things are true, is it not time 

 to have done once for all with the pre-Darwinian metaphysical 

 notion of species as something which resides in germ cells and 

 is handed down by a substance of heredity?" 



This brings us to a consideration of his philosophical and 

 metaphysical writings to which the last ten years of his life 

 were devoted almost exclusively. The publications of this 

 period include some eighteen or twenty papers on philosophical 

 subjects, culminating in the book into which he put the best 

 efforts of his life, and by which he hoped to be longest remem- 

 bered, viz.: "The foundations of zoology' 7 (1899). This book 

 consists of a series of lectures which were originally delivered 

 at Columbia University, and were published in the Biological 

 Series of that institution. It deals with many subjects funda- 

 mental not only to zoology, but to science and philosophy in 

 general. The keynote of this book is found in the following 

 extracts from the introductory lecture: "I shall try to show 

 that life is response to the order of nature — in fact, this thesis 

 is the text of most of the lectures ; but if it be admitted, it fol- 

 lows that biology is the study of response, and the study of 

 that order of nature to which response is made is as well within 

 its province as the study of the living organism which re- 

 sponds." Among such responses to the order of nature are 

 various forms of adaptation, correlation, instinct, intelligence, 

 volition, and responsibility, and the question arises as to 

 whether such responses are mechanical. "I am myself unable 



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