370 THE HISTORY OF CREATION. 
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 the 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, unhindered 
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. Curiously enough, Wagner says nothing of 
the numérous 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- 
