40 SPECIFICITY OF THE BLOOD OF VERTEBRATES 



(4) horse, pig, and rabbit each group being positively distinguished from 

 the others, each individual of each group being distinguishable not only 

 from the members of the other groups but from each member of the same 

 group, by the differences in the quantities and ratios of Na and K. 



In the first group (dog and cat) the Na content of the corpuscles is 

 about four-tenths less than the quantity in the serum, while that of K is 

 practically identical in both serum and red corpuscles. 



In the second group (bullock, sheep, and goat) the Na is a little over 

 half the proportion in the serum, while the K is about 3 times greater than 

 the quantity in the serum. 



In the third group (man representing the primates) the Na content is 

 only about one-fourth that of the serum, while the K is about 16 times 

 greater than in the serum. 



In the fourth group (horse, pig, and rabbit) Na is absent from the cor- 

 puscles, while the quantity in the serum is about the same as in the first 

 and second classes. On the other hand, the K content of the corpuscles 

 is about 20 times greater than in the serum. In this class are individual 

 representatives of two classes of ungulates (horse and pig) and one class 

 of rodents. Whether or not Na is present in the red corpuscles of the rabbit 

 might possibly be regarded as an open question, since Botazzi and Capelli 

 found it (only 0.077 per cent) and Abderhalden did not, but one would be 

 inclined to accept the work of Abderhalden, whose analysis was of the 

 blood from 12 rabbits. 



In animals having nucleated red corpuscles it has been found by 

 Botazzi and Capelli that while the corpuscles contain Na it is in very low 

 percentage. In the chicken the Na is particularly low, but the K percent- 

 age is quite high. In the animals of this group (chicken, tortoise, frog, 

 and toad) there is no difficulty in differentiating one genus from the others 

 by the differences in the ratios of the Na and K : in the chicken 1 : 29, and 

 in the frog, toad, and tortoise 1 : 7.9, 1 : 18, and 1:11, respectively. 



From these records of the Na and K contents of the corpuscles the 

 following conclusions may be drawn: (1) that the Na and K percentages 

 are in inverse but not proportional relationship; (2) that carnivora, as 

 represented by the dog and cat, are characterized by a high Na content and 

 a very low K content, the percentage of K being practically the same as 

 in the serum ; (3) that in ruminants the Na content is about one-fifth lower 

 than in carnivora, and the K content nearly 3 times higher; (4) that in 

 human blood the Na content is somewhat over one-fourth the quantity in 

 carnivora, while the K content is about 12 times higher; (5) that in the 

 classes represented by the horse, pig, and rabbit Na is absent, and the K 

 content reaches its highest, being about 20 times higher than in carnivora; 



(6) that in birds, as represented by the chicken, the Na is the lowest noted 

 in any of the groups (excluding Botazzi and Capelli's figure for the rabbit), 

 while the K is very high, but not so high as in the horse, pig, and rabbit; 



(7) that the ratios of Na to K in the sera of all animals are practically 

 identical; (8) that the ratios of Na to K in the corpuscles are sufficiently 

 different to be of considerable importance in zoological differentiation. 



