IN RELATION TO ZOOLOGICAL DISTINCTION. 



43 



TABLE 16. The percentages of proteins, globulins, and albumins, and the 

 protein quotients of the serum of different animals. 



* Hammarsten, Archiv f. ges. Physiologic, 1878, xvn, 413. Halliburton, Journal 

 of Physiology, 1886, vn, 319. Abderhalden, loc. cit. Hoffmann, loc. cit. Howell 

 (quoted by Halliburton). Wolfenden (quoted by Halliburton). 



t The pleuroperitoneal fluid may have been mixed with the blood. 



In birds the total protein content is low and approaches that of cold- 

 blooded animals rather than that of mammals. The marked differences 

 in the percentage of globulins and albumins and the protein quotients of 

 the chicken and pigeon are very striking. 



The records of the protein content of the bloods of cold-blooded ani- 

 mals are much more variable than in the case of mammals, and it seems 

 that further inquiry should render possible certain sharply defined generic 

 distinctions. 



Since the total percentage of proteins is a variable one under both 

 normal and abnormal conditions, and since the protein quotient seems to 

 be fairly constant under both normal and abnormal conditions, the latter 

 is by far the more important factor in indicating generic differentiation. 

 The very much higher percentage of albumins in mammals is positive, 

 and it is higher both relatively and absolutely than in birds and in cold- 

 blooded animals generally. In man, the rabbit, and the dog the proportion 

 of albumins is higher than that of globulins, but in the bullock and horse 

 it is lower. The quotients for man, dog, and rabbit are 0.688, 0.429, and 

 0.408 respectively, and for the horse and bullock 1.779 and 1.252 respec- 

 tively. These differences are so marked, both as regards class and individ- 



