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the presence of more or less granular matter, white, and 

 larger than the red corpuscles. 



In examining the circulation under the microscope, we 

 are struck with the adhesive character of the leucocytes as 

 compared with the red corpuscles. The latter circulate with 

 wonderful rapidity in the centre of the vessel, while the 

 leucocytes have a tendency to adhere to the sides, moving 

 along slowly, and occasionally remaining for a time entirely 

 stationary, until they are swept along by a change in the 

 direction or force of the current. 



Their size varies somewhat, even in any one fluid, 

 as the blood. Their average diameter may be stated as 

 Y-fQ-Q- of an inch. It is in pus, where they exist in greatest 

 abundance, that their microscopic characters may be studied 

 with greatest advantage. In this fluid, after it is discharged, 

 the corpuscles sometimes present remarkable deformities. 

 They become polygonal in shape, and sometimes ovoid ; oc- 

 casionally presenting projections from their surface, which 

 give them a stellate appearance. These alterations, how- 

 ever, are only temporary ; and after from twelve to twenty- 

 four hours, they resume their globular shape. On the addi- 

 tion of acetic acid they swell up, become transparent with a 

 delicate outline, and present in their interior one, two, three, 

 or even four rounded nuclear bodies generally collected in a 

 mass. This is rather to be considered as a coagulation of a 

 portion of the corpuscle, than a nucleus brought out by the 

 action of the acid, which renders the corpuscle transparent ; 

 though in some it is seen through the granules without the 

 addition of any reagent. This appearance is produced, 

 though more slowly, by the addition of water. 



Leucocytes vary considerably in their external characters 

 in different situations. Sometimes they are very pale and 

 almost without granulations, while at others they are filled 

 with fatty granules, and are not rendered clear by acetic 

 acid. As a rule, they increase in size and become granular 

 when confined in the tissues. In colostrum, when they are 



