54 THE EVOLUTION OF LIVING BEINGS. 



garden, and by selfing them or by mating them with 

 other individuals of identical constitution, but of dif- 

 ferent sex, we can multiply them and thus obtain new 

 species consisting of as many individuals as we choose 

 to raise. 



Evidently it does not matter from which species the 

 gametes which form the zygote, that sprouts to the 

 polygametic hybrid, are derived ; it is not even neces- 

 sary that these gametes should be derived from pure 

 species; they can just as well be derived from hybrids, 

 because the result has nothing to do with the origin 

 of these gametes, but only with their constitution. 



Consequently new species can originate, as well in 

 a monophyletic as in a polyphyletic way. 



The spot, where the mating of such gametes takes 

 place, is of course as indifferent to the effect as the 

 origin of these gametes, consequently species can arise 

 polytopically e. g. the same species may be born at 

 different spots. That this is a fact can easily be shown. 



By crossing (Baur 2d edition p 94) a homozygous 

 yellow Antirrhinum majus with a homozygous red 

 A. majus we obtain among the segregates in F 2 ho- 

 mozygous yellow-red species, which however we can 

 obtain just as well, by crossing a heterozygous red 

 form of the Linneon A . majus with a heterozygous pale 

 yellowred form of the same Linneon. 



This as an example, that the same species can arise 

 in different ways. 



That the same species can arise at different spots 

 and at different times, is ofcourse an experience of 

 the commonest sort. A rather striking example is 



