LAMARCK AND MR. DARWIN. 259 



" natural selection " in connection with the " origin of 

 species " has led him, in spite of himself, and in spite 

 of his being on his guard (as is clearly shown by the 

 paragraph on page 63 "Natural Selection," above re- 

 ferred to), to regard " natural selection " as in some 

 way accounting for variation, just as the use of the 

 dangerous word " spontaneous," though he is so often 

 on his guard against it, and so frequently prefaces it 

 with the words " so-called," would seem to have led 

 him into very serious confusion of thought in the pas- 

 sage quoted at the beginning of this paragraph. 



For after saying that he had under-rated " the fre- 

 quency and importance of modifications due to spon- 

 taneous variability," he continues, " but it is impossible 

 to attribute to this cause the innumerable structures 

 which are so well adapted to the habits of life of each 

 species." That is to say, it is impossible to attribute 

 these innumerable structures to spontaneous variability. 



What is spontaneous variability ? 



Clearly, from his preceding paragraph, Mr. Darwin 

 means only "so-called spontaneous variations," such as 

 " the appearance of a moss-rose on a common rose, or 

 of a nectarine on a peach-tree," which he gives as good 

 examples of so-called spontaneous variation. 



And these variations are, after all, due to causes, but 

 to unknown causes; spontaneous variation being, in 

 fact, but another name for variation due to causes 

 which we know nothing about, but in no possible sense 

 a cause of mriatio?i. So that when we come to put 

 clearly before our minds exactly what the sentence we 

 are considering amounts to, it comes to this : that it is 



