232 



MANUAL OF PHYSIOLOGY. 



The shape of the corpuscles differs indifferent 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 camelidse, 

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

 mammalian vertebrates. 



FIG. 99. 



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

 ments below are in fractions of a millimetre: 1. Amphiuma, T T 5 X sV 2. Proteus, 

 A X A- 3. Frog, A X B V 4. Pigeon, ^ X rk- 5. Elephant, T J g . 6. Man, T ^. 7. Dog, 

 T J 5 . 8. Horse, T T . 9. Goat, 2 | 3 . 10. Musk-deer, j| 3 . 



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

 tical plates, which are slightly convex on each side, and contain 

 a distinct oval nucleus in their centre. 



The sizes of the corpuscles varies greatly in different classes of 

 animals, but is strikingly constant in the same class. A glance 



