190 DARWmiANA. 



establislied, it follows almost of course that tlie very 

 nearly-related species in Central Asia, in Japan, in 

 California, and even our own live-oak with its Mexican 

 relatives, may probably enough be regarded as early 

 offshoots from the same stock with Q. Ilex. 



In brief — not to continue these abstracts and re- 

 marks, and without reference to Darwin's particular 

 theory (which De Candolle at the close very fairly con- 

 siders) — if existing species, or many of them, are as 

 ancient as they are now generally thought to be, and 

 were subject to the physical and geographical changes 

 (among them the coming and the going of the glacial 

 epoch) which this antiquity implies ; if in former 

 times they were as liable to variation as they now are ; 

 and if the individuals of the same species may claim a 

 common local origin, then we cannot wonder that " the 

 theory of a succession of forms by deviations of ante- 

 rior forms " should be regarded as " the most natural 

 hypothesis," nor at the general advance made toward 

 its acceptance. 



The question being, not, how plants and animals 

 originated, but, how came the existing animals and 

 plants to be just where they are and what they are, 

 it is plain that naturalists interested in such inquiries 

 are mostly looking for the answer in one direction. 

 The general drift of opinion, or at least of expectation, 

 is exemplified by this essay of De Candolle ; and the 

 set and force of the current are seen by noticing how 

 it carries along naturalists of widely different views 

 and prepossessions — some faster and farther than oth- 

 ers — but all in one way. The tendency is, we may say, 

 to extend the law of continuity, or something analo- 



