OBJECTIONS A GAINS T E VOL UTION. 199 



of knowing whether it were the first or the last of 

 its race." 



Regarding the laws governing such extraordinary 

 births, Mivart is unable to vouchsafe any informa- 

 tion. He is, however, of the opinion, that sufficiently 

 numerous instances of such births are known to jus- 

 tify one in accepting the theory. If it could be 

 demonstrated to be true, it would at once remove 

 all the difficulties presented by the lack of geolog- 

 ical time, the absence or paucity of transitional forms, 

 the origin of rudimentary organs, and the elimina- 

 tion of variations by crossing ; difficulties which 

 natural selection -has been thus far impotent to re- 

 move. As is manifest, Mivart's theory does not 

 explain the facts it deals with ; it simply refers the 

 sudden changes demanded to the action of unknown 

 internal forces. This, at bottom, is not unlike the 

 theory of the German botanist, Nageli, who would 

 account for development by assuming that there ex- 

 ists in all organisms an internal tendency towards 

 progression. But this is obviously only another way 

 of expressing the action of the "perfecting principle" 

 of Aristotle, as Darwin's theory of chance variations 

 is but a modification of the conjecture of " fortuity 

 in nature," of old Empedocles. 



Concerning Weismann's theory of heredity, 

 Haeckel's speculations on perigenesis, Jager's notions 

 regarding soul-stuff, and Brooks' hypothesis respect- 

 ing both heredity and variation, we need say noth- 

 ing except that Weismann's theory has many points 

 of weakness, that the views of Haeckel and Jager are 

 based mostly on fancy, and that the hypothesis of 



