BLOOD-CORPUSCLES. 79 



with the fibrin and the portion of the serum that is soaked 

 in it, the blood- corpuscles, or blood-cells. Of these there are 



Fig. 24.* 

 Mammals. Birds. Eeptiles. Amphibia. Fish. 



* The above illustration is somewhat altered from a drawing, by Mr. 

 Gulliver, in the Proceed. Zool. Society, and exhibits the typical characters 

 of the red blood-cells in the main divisions of the Vertebrata. The 

 fractions are those of an inch, and represent the average diameter. In 



