EVIDENCE FROM BLOOD TESTS 77 



dence, for the reactions obtained with the bloods of 

 Simiidae [i. e., Man-like Apes] closely resemble those 

 obtained with human blood, the bloods of Cercopi- 

 thecidae [Old World Monkeys] came next, followed 

 by those of Cebidse and Hapalidae [New World 

 Monkeys and Marmosets] which gave but slight 

 reactions with anti-human serum, whilst the blood 

 of Lemuroidea gave no indication of blood-relation- 

 ship." (p. 2). "A perusal of the pages relating to 

 the tests made upon the many bloods I have exam- 

 ined by means of precipitating anti-sera, will very 

 clearly show that this method of investigation per- 

 mits of our drawing certain definite conclusions. It 

 is a remarkable fact . . . that a common property 

 has persisted in the bloods of certain groups of ani- 

 mals throughout the ages which have elapsed during 

 their evolution from a common ancestor, and this in 

 spite of differences of food and habits of life. The 

 persistence of the chemical blood-relationship be- 

 tween the various groups of animals serves to carry 

 us back into geological times, and I believe we have 

 but begun the work along these lines, and that it will 

 lead to valuable results in the study of various prob- 

 lems of evolution" (pp. 2-4). 



The general conclusions on interrelationships, so 

 far as they are of particular interest for our purpose, 

 reached by Nuttall and Graham-Smith as the result 

 of many thousands of blood tests, may be sum- 

 marized as follows: 



(1) If sufficiently strong solutions be used and 



