EXAMINATION OF ANIMAL FLUIDS. 



681 



of cancer and the agglomerated nuclei are shown in Figs. 390, 

 391 (after Donaldson). 



FIG. 389. 



FIG. 391. 



FIG. 390. 



EXAMINATION OF ANIMAL FLUIDS. 



Blood. To examine blood microscopically it is only necessary 

 to press a small drop between two pieces of glass, until it is flat- 

 tened out into a thin layer. A number of yellow, round, 

 bi-concave disks will then be seen, varying in diameter from the 

 l-5000th to the 1- 3000th of an inch, the average size being about 

 l-4000th of an inch. These disks have a bright margin, and a 

 dark centre ; or a bright centre and a dark margin, according to 



FIG. 392. 



FIG. 393. 



the focus in which they are placed. (Fig. 392.) Exposure to 

 the atmosphere causes the edges of the corpuscles to lose their 

 smooth outline, and become irregularly notched or serrated, 

 and sometimes beaded. (Fig. 393 B.) 



The corpuscles vary in size in different animals. Thus in 

 birds, fishes, and reptiles they are elliptical and flattened, and 

 exhibit a distinct nucleus, which is generally oval. In the camel 

 tribe they are elliptical and bi-convex. 



