ii6 LOUIS AGASSIZ. [CHAP. xvm. 



the shock of comets, etc., etc. Later, since October, 

 1860, when Herbert Spencer, in his "First Principles of 

 a New System of Philosophy," gave the following defini- 

 tion : " Evolution is the integration of matter and con- 

 comitant dissipation of motion," everything in natural 

 history, and in social, political, economical, historical, 

 and philological sciences, is evolution. It is not that the 

 word "evolution" was not used before in natural his- 

 tory, although, curiously enough, Darwin did not use it 

 once in his " Origin of Species " ; for since the second 

 half of the eighteenth century we find it used by 

 Bonnet, and afterward by Laurillard, the assistant and 

 right hand of George Cuvier, who recalled the observa- 

 tions of Bonnet on evolution. If Lamarck had used it 

 in his " Philosophic Zoologique," his theory might have 

 had another destiny during his lifetime. Darwin had 

 the acuteness to see what a capital handle it would 

 make for his theory, and as soon as he saw it in Spen- 

 cer's work, he transferred the word into all his other 

 works, speaking constantly of the " principles of evo- 

 lution." His sympathizers took to evolution, and now 

 evolution is everywhere. It has dethroned revolution 

 completely. The word "evolution" a fait fortune ac- 

 cording to a French proverb. 



It is the only tie certainly a very slender and 

 elastic one --between all those who call themselves 

 Darwinians ; l although the word does not occur at all 

 in the " Origin of Species." In this connection a few 

 quotations from "Asa Gray's Life and Letters" are 



1 There is only one exception, Alphonse de Candolle, who used the 

 word " transformism " as preferable to " evolution," because, as he says, 



