44 THE SCIENTIFIC EVIDENCES OF 



tion of a scientific theory is furnished when it 

 enables us correctly to pj-edict discoveries. Such 

 a corroboration is afforded in this instance ; for 

 Professor Huxley, speaking in 1870, said, " If 

 the expectation raised by the splints of the 

 horses that, in some ancestor of the horses, 

 these splints would be found to be complete 

 digits, has been verified, we are furnished with 

 very strong reasons for looking for a no less 

 complete verification that the three-toed plagio- 

 lopJmsASke. ' avus ' of the horse must have 

 had a five-toed ' atavus ' at some earlier period. 

 No such five-toed ' atavus,' however, has yet 

 made its appearance." But since then the 

 " atavus " has made its appearance, if not with 

 five complete toes, at least with four complete 

 and one rudimentary; and any day we may 

 hear that Professor Marsh has found in still 

 earlier strata a more primitive form with all five 

 toes complete. 



