10 THE BLOOD. 



Diameter. Diameter. 



Water rat, ^i^ Opossum, ^ T 



Porcupine, ^ 7 Kangaroo, ^ 3lr 



Beaver, ^I T 



Guinea-pig, ^^ L. diam. S. diam. 



Rabbit, -3-gLjy Dromedary (oval), . . . T2 V -g^- 



Two-toed sloth, Y -^ T Camel (oval), . . . ^ T fa 



^'s/i65. 



Corpuscles Oval. 



Long Short Long Short 



Diameter. Diameter. Diameter. Diameter. 



Perch, ToV? TW Pike, FO I O'O' irs^s" 



Carp, n'^fi 'wfas Eel, . . . . . lA's" W^F 



Enumeration of the Blood- Corpuscles. In most of the quantitative analyses of the 

 blood, the proportion of moist corpuscles to the entire mass of blood is stated to be a 

 little less than one-half. This estimate is necessarily rather rough ; and it would be in- 

 teresting to ascertain, if possible, the normal variations in the proportion of corpuscles, 

 under different conditions of the system, particularly as these bodies play so important a 

 part in many of the functions of the organism. Estimates of this kind have lately been 

 made by Malassez, who has devised a method, more accurate than those employed before, 

 for the actual enumeration of the red corpuscles, in which, it is stated, the error does not 

 amount to more than two or three per cent. The process employed is the following : 



