Chap. XV.] CONCLUSION. 297 



merable periods in the earth's history certain elemental 

 atoms have been commanded suddenly to flash into 

 living tissues ? Do they believe that at each supposed 

 act of creation one individual or many were produced ? 

 Were all the infinitely numerous kinds of animals and 

 plants created as eggs or seed, or as full grown ? and in 

 the case of mammals, were they created bearing the 

 false marks of nourishment from the mother's womb ? 

 Undoubtedly some of these same questions cannot be 

 answered by those who believe in the appearance or 

 creation of only a few forms of life, or of some one form 

 alone. It has been maintained by several authors that 

 it is as easy to believe in the creation of a million beings 

 as of one ; but Maupertuis' philosophical axiom " of least 

 action" leads the mind more willingly to admit the 

 smaller number ; and certainly we ought not to believe 

 that innumerable beings within each great class have 

 been created with plain, but deceptive, marks of descent 

 from a single parent. 



As a record of a former state of things, I have retained 

 in the foregoing paragraphs, and elsewhere, several 

 sentences which imply that naturalists believe in the 

 separate creation of each species ; and I have been much 

 censured for having thus expressed myself. But un- 

 doubtedly this was the general belief when the first 

 edition of the present work appeared. I formerly spoke 

 to very many naturalists on the subject of evolution, 

 and never once met with any sympathetic agreement. 

 It is probable that some did then believe in evolution, 

 but they were either silent, or expressed themselves so 

 ambiguously that it was not ea^y to understand their 

 meaning. Now things are wholly changed, and almost 

 every naturalist admits the great principle of evolution. 



