ii HEADS OF EVIDENCE 97 



between the living fauna and the extinct 

 fauna of the great continents and islands 

 of the globe, which are most widely 

 separate from others, and suggesting 

 that, as the likeness has been continuous, 

 so it must be due to local continuities of 

 growth. Fourthly there are the wonder- 

 ful facts of Embryology, which are full 

 of suggestions to a like effect. Then 

 there is another head of evidence, making 

 a fifth, which Mr. Spencer is disposed to 

 add to the other four a head of evidence 

 which I venture to regard as even more 

 interesting and significant than any other 

 that, namely, which rests on the occur- 

 rence of what are called Rudimentary 

 Organs in many animal frames that is 

 to say, organs, or bits of structure, which, 

 in those particular creatures, are almost 

 or entirely devoid of any functional use, 

 but which correspond, more or less, with 



similar organs in other animals where 

 H 



