DARWINISM AND EVOLUTION DEFINED. n 



of descent. The theory of descent (with which phrase or- 

 ganic evolution may be practically held as a synonym) is, 

 then, simply the declaration that the various 

 Theory of living: as well as the now extinct species of 



descent denned, 



organisms are descended from one another and 

 from common ancestors. It is the explanation of the origin 

 of species accepted in the science of biology. (The natural 

 question about the first species or the first several, if they 

 appeared simultaneously, will receive attention later; the 

 theory of descent explains the origin of kinds of life, not 

 the origin of life.) If such a summary disposal of the 

 theories of spontaneous generation and divine creation is too 

 repugnant to my readers to meet with their toleration, then, 

 as Delage has pertinently said in connection with a similar 

 statement in his great tome on ''Heredity," my book and such 

 readers had better immediately part company; we do not 

 speak the same language. 



The theory of descent, long before it was fully set forth 

 by Darwin in 1858 together with a definite and wholly 

 p D . plausible causo-mechanical explanation of it, 

 ian recognition had been foreshadowed and even fairly ex- 

 of descent. p H c i t i y formulated by various philosophical 



naturalists; among others, Goethe (1790) in Germany, 

 Erasmus Darwin (1794) (grandfather of Charles Darwin) 

 in England, Lamarck (1809) very definitely in France, 

 Chambers in the "Vestiges of the Natural History of 

 Creation" (1844), and Wallace (1858) coincidently with 

 Darwin himself had all recognised descent as the only pos- 

 sible scientific explanation of the origin of species and had 

 offered explanations of the causal factors of this descent. 

 Even in the far older writings 2 of the Greeks, most con- 

 spicuously perhaps in the pages of Aristotle (350), may be 

 found phrases and pages foreshadowing those of Lamarck, 

 Wallace, and Darwin. But it was not until Darwin had 

 backed up the formulation of the descent theory with that 



