370 THE HISTORY OF CREATIOX. 



turbed breeding of a commencing variety of colonists in a 

 new territory continues without its mingling with subse- 

 quent immigrants of the same species, the oftener a new 

 species will arise out of tlie variety." 



Every one will agree with these three propositions of 

 Moritz Wagner's. But we must consider his view, that the 

 migration and the subsequent isolation of the emigrant in- 

 dividuals is a necessary condition for the origin of new 

 species, to be completely erroneous. Wagner says, " with 

 out a long-enduring separation of colonists from their former 

 species, the formation of a new race cannot succeed — selection, 

 in fact, cannot take place. Unlimited crossing, unliindered 

 sexual mingling of all individuals of a species will always 

 produce uniformity, and drive varieties, whose characteris- 

 tics have not been fixed throughout a series of generations, 

 back to the primary form." 



This sentence, in which Wagner himself comprises the 

 main result of his investigations, he would be able to defend 

 only if all organisms were of separate sexes, if every origin 

 of new individuals were possible only by the mingling of 

 male and female individuals. But this is by no means 

 the case. Cmiously enough, Wagner says nothing of 

 the numerous hermaphrodites which, possessing both the 

 sexual organs, are capable of self-fructification, and like- 

 wise nothing of the countless organisms which are not 

 sexually differentiated. 



Now, from the earliest times of the organic history of the 

 earth, there have existed thousands of organic species 

 (thousands of which still exist) in which no difference of 

 sex whatever exists, and, in fact, in which no sexual propa- 

 gation takes place, and which exclusively reproduce them- 



