64 EVOL UTION AND NA TURAL THEOL G Y. 



bred out, and the race might again begin to 

 vary in the direction of increased speed. 



V. " Certain transitional forms are absent, 

 which might have been expected to be 

 present." 



This objection assumes that the geological 

 record is more perfect than was supposed by 

 Darwin. Lubbock* points out (on Ly ell's 

 authority) that the Quaternary Mammalia are 

 frequently intermediate between existing species. 

 Thus, the European and American bisons are 

 blended by remains meeting in Bison Priscus, 

 and the brown and grizzly bears meet by im- 

 perceptible gradations in the cave bear ; but 

 no naturalist would class the existing bisons or 

 bears as varieties, though their common origin 

 must be regarded as proved. It would be 

 highly interesting and important to ascertain 

 whether those distinct species which are geo- 

 logically one, are still capable of producing 

 fertile offspring, if crossed. 



But the Quaternary period is the geological 

 age immediately preceeding our own ; and 

 yet how many species which then existed in 



* " Prehistoric Times," ch. ix. 



