BLOOD CELLS. 



549 



Wharton Jones, however, says there is no subdivision of 

 the nucleus. 



If we examine a drop of blood under the microscope, 



they appear when fresh drawn (magnified 250 diameters). 



the corpuscles aggregate themselves together like rolls of 

 coins, fig. 285, No. 3, which present a kind of network so 

 long as they remain suspended in their liquor sanguinis. 

 After the lapse of a few minutes, the fibrin, from its 

 elasticity, contracts more and more, and a yellow fluid, 

 called serum, is pressed out, or, in other words, the com- 

 ponents of the liquor sanguinis, with the exception of the 

 fibrin ; and only a shrunken, jelly-like mass remains. 



The blood corpuscles of the lower animals Mr. Gulliver 

 has especially studied. In the blood corpuscles of birds, and 

 animals below them, there are nuclei ; but the cells, instead 

 of being round, as in the human subject, are elliptical and 

 larger. The corpuscles in Mammifera in general are like 

 those of man in form and size, being a little larger or 

 smaller. The most marked exception is in the blood of 



