458 THE CAUSES OF THE 



XI 



you accept Mr. Darwin's hypothesis, and see reason 

 for believing that the whalebone whale and the 

 whale with teeth in its mouth both sprang from a 

 whale that had teeth, and that the teeth of the 

 foetal whale are merely remnants recollections, 

 if we may so say of the extinct whale. So in 

 the case of the horse and the rhinoceros : suppose 

 that both have descended by modification from 

 some earlier form which had the normal number 

 of toes, and the persistence of the rudimentary 

 bones which no longer support toes in the horse 

 becomes comprehensible. 



In the language that we speak in England, and 

 in the language of the Greeks, there are identical 

 verbal roots, or elements entering into the com- 

 position of words. That fact remains unintellig- 

 ible so long as we suppose English and Greek to 

 be independently created tongues; but when it is 

 shown that both languages are descended from 

 one original, we give an explanation of that 

 resemblance. In the same way the existence 

 of identical structural roots, if I may so term 

 them, entering into the composition of widely 

 different animals, is striking evidence in favour of 

 the descent of those animals from a common 

 original. 



To turn to another kind of illustration : If you 

 regard the whole series of stratified rocks that 

 enormous thickness of sixty or seventy thousand 

 feet that I have mentioned before, constituting the 



