WHAT IS PHYSICAL LIFE 



crops grass, but goes where he can live 

 on an exclusively fish diet. Likewise, the 

 hippopotamus is shown to be a modified 



Pig- 

 Where blood relationship exists, but 



is distant, these reactions are proportion- 

 ately faint, but where no reactions occur 

 there is no relationship at all. Thus, ge- 

 ology indicates that birds are descended 

 from reptiles, and oddly enough, the blood 

 of a bird shows a distinct, though very 

 faint, reaction with the blood of a snake, 

 but none whatever with that of the winged 

 bat or the flying squirrel, for these are 

 mammals. 



On the other hand, the marsupials, once 

 such a great family, but now reduced to 

 the kangaroo, the opossum, and a small 

 creature in South America, have now not 

 a single blood relation left. As to man, 

 he has no relationship to monkeys, but the 

 blood of anthropoid apes shows a very 

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