228 Lr^'TTFR PT'T?r \\K 



tested. He thus iiemonitnOcU, lur example, tliat 

 lizards and lerpents are more doaely related than 

 turtles and crocodiles, but that all these reptiles 

 are nearer to one another than they are to birds, 

 and nearer to birds than to mammals. 



He showed that the dog carries in every drop 

 of its blood chemical proof of closer relationship 

 with wdres, and foxes, and jackals of every 

 species than with any member whate the 



cat family. Similarly, all cats — tigers, lions, 

 leopards, along with the domestic tabby — give 

 proof, in the chemical constitution of their blood, 

 of a common origin. And, bringing the com- 

 parison still nearer home, the blood of man is 

 more like that of the chimpanzee, the gorilla, and 

 the orang, than it is hke that of any other crea- 

 tures; and the monkey tribes of the Old World 

 are more numlike in the constitution of their blood 

 than are the monkeys of the New World. 



Dr. Xuttall's experiments comprised sixteen 

 thousand individual tests, with a total of at 

 least 586 species of mammals, birds, reptiles, 

 batrachians, fishes, and crustaceans, coming from 

 all parts of the globe. The biological implica- 

 tions of his experiments have been commented 

 upon as follows: 



"Doubtless some hundreds of thousands of 

 years have elapsed since the direct ancestors of 



