THE RED CORPUSCLES. 225 



appear to be pale orange, but when in masses the red becomes 

 apparent. 



The shape of the corpuscles differs in different classes of animals. 

 In man and all mammalia they are disks which are concave on 

 each side, and rounded off at the margin. The only class of 

 mammals which form an exception to this rule are the camalidse, 



FIG. 99. 



Diagram of the relative sizes of red corpuscles of different animals. The 

 measurements below are in fractions of an inch : 1. Amphiuma, T ^ X yV 

 2. Proteus, T \ X ? V 3. Frog, ^ X *V- 4 - Pigeon, ^ X ?fa. 5. Elephant, 

 T fo. 6 Man, T ^. 7 Dog, T fo. 8. Horse, T T . 9. Goat, ^j. 10. Musk- 

 deer, T } . 



whose red corpuscles are elliptical in shape, like those of all non- 

 mammalian vertebrates. 



The corpuscles of birds, amphibia and fish are flattened ellip- 



19 





