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 
