LEADING ARGUMENTS FOR DESCENT 183 



In the specific instance of man, Rossle shows 

 that the test of blood reaction between man and 

 the higher apes affords no proof whatsoever of 

 a close evolutionary relationship. 7 



One reason, no doubt, why these blood-tests 

 aroused some interest at first, is that the word 

 "blood-relationship" in ordinary language implies 

 common descent; in science, however, it merely 

 means chemical similarity, such as may exist in 

 the flesh, the nerve-substance, the bone, of ani- 

 mals of a very similar structural type. 



Finally we approach the subject of the so-called 

 rudimentary organs. To make the meaning of 

 this term clear, consider the case of the whale, 

 which has two front paddles corresponding to the 

 forelegs of quadrupeds, but no external appen- 

 dages reminding one of the hind legs; its body is 

 in fact cylindrical. On examining the skeleton, 

 however, we find in the Greenland whale that the 

 hip-bone, the thigh-bone and the shin-bone are 

 visibly present, though in a reduced, atrophied and 

 useless condition. Here we have rudimentary 

 organs that are permanent; temporary rudiments 

 are likewise found in the embryos of certain 

 whales, the embryo having at first a dense cover- 

 ing of hair and numerous teeth, which appendages 

 are presently atrophied and lost. The teeth are 

 thought to be probably of use in the growth of 



T C/. Wasmann, "The Problem of Evolution," pp. 67, 68. 



