INTRODUCTION 7 



Other Body Tissues Which Re\eal Evolutionary Kinship 

 the blood 



The actual existence of evolutionary kinship has ah^eady been revealed 

 by many other organs and tissues of the body. The blood, for example, has 

 been most outspoken in this respect. Human blood scrum injected into the 

 rabbit produces what is known as anti-buman scrum. This latter serum 

 affords an exceedingly delicate test for iiuman blood, either fresh or in the 

 form of old and dried clots. If the blood tested be that of a domestic animal, 

 such as the horse, sheep, pig or fowl, no reaction results from this scrum. 

 Anti-horse serum, anti-sheep serum, anti-pig serum and anti-fowl scrum 

 may be prepared in a similar manner. These are sensitive agents for detect- 

 ing the presence of horse, sheep, pig or fowl blood. An anti-serum may also 

 be made for all animals and tests thus provided to detect the blood of similar 

 species. 



Investigations have shown that these blood tests may be employed 

 to determine the degree of relationship existing between different kinds of 

 animals. A prompt and often strong reaction is obtained only from the blood 

 of the same species, while the blood of closely allied species, such as that of 

 the horse and donkey, gives a weaker, slower precipitation. 



These precipitin tests support the supposition that there is some distant 

 relation between the old-world monkeys, apes and man. They also make clear 

 a less intimate relationship between the new-world monkeys and the human 

 stock. The lowest animals classified among the primates, the lemurs, give no 

 sign of blood relationship with man, although there is some indication of 

 such a kinship with the lower new-world monkeys. Tarsius, however, is an 

 exception to this rule. It bears a closer blood relation to man, simia and gib- 

 bon than it does to macacus, the new-world monkeys or the cat. 



Hcmal tests demonstrate a relationship among all carnivora closer than 

 exists between carnivores and ungulates, while cetacean forms (whales and 



