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kind appear to me to be entirely unaccountable and 

 inexplicable, but they cease to be so if 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 compre- 

 hensible. 



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 composition of 

 words. The fact remains unintelligible 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, the Sanscrit, w r e 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 enor- 

 mous thickness of sixty or seventy thousand feet that 

 1 have mentioned before, constituting the only record 

 we have of a most prodigious lapse of time, that time 

 being, in all probability, but a fraction of that of which 

 we have no record ; — if you observe in these successive 

 strata of rocks successive groups of animals arising and 



