THE GERM-PLASM THEORY 61 



of which do not come within the domain of 

 physics. 



One would imagine that if there were any fields 

 in which the flower of humility ought to be found 

 flourishing those fields would be in the country 

 of science, when one reflects that it is not merely 

 of enormous difficulty to compass an irrefragable 

 theory, but really an immense task to establish 

 some of the facts on which vast superstructures 

 of theory rest. Let us consider one example, an 

 example which has been more often quoted than 

 any other in evolutionary literature the horse. 

 The ancestry of the horse, in the first place, has 

 been the commonplace of evolutionary text-books. 

 One of the last of the many little manuals on this 

 subject brought out by rival and enterprising 

 firms of publishers tells us that " this great service, 

 the affording of unquestionable proof of this 

 momentous theory [of transformism] mankind 

 owes to its trusty servant the horse." Yet, as has 

 been pointed out time and again, there are various 

 great difficulties still not cleared up in connexion 

 with the much vaunted horse-pedigree, diffi- 

 culties which render it quite absurd to assert that 

 this affords " unquestionable " proof of the theory 

 in whose favour it is brought forward. Sedgwick,* 

 in his masterly work, states the case fully and 

 fairly. " So far as the characters mentioned are 

 concerned, we have here a very remarkable series 

 of forms which at first sight appear to constitute 

 a linear series with no cross connexions. Whether, 

 however, they really do this is a difficult point to 



* Student's Text Book of Zoology, vol. 11, p. 600. 



