214 LECTURE IX. 



Pus consists essentially of cells, which in their ordinary 

 condition lie close to one another (Fig. 63, (7, and be- 

 tween which a small quantity of intercellular fluid (pus- 

 serum) exists. Within the pus-corpuscles themselves lies 

 a substance which is likewise provided with a great quan- 

 tity of water ; for nearly every specimen of pus, although 

 it may look very thick when fresh, contains such a large 

 amount of water that it loses a great deal more by eva- 

 poration than a corresponding quantity of blood. The 

 latter only gives the impression of being more watery 

 because it contains a great deal of free (intercellular), 

 but relatively little intracellular, fluid, whilst in pus on the 

 contrary there is a greater quantity of water in the cells, 

 and less without them. When then reabsorption takes 

 place, the greatest part of the intercellular fluid first dis- 

 appears, and the pus-corpuscles draw nearer to one an- 

 other ; soon, however, a part of the fluid from the cells 

 themselves also vanishes, and in propor- 

 tion as this is the case, they become 

 -I I smaller, more irregular, angular, and un- 



** even, they assume the most singular 



& ^^ ^3 ^ 



forms, lie closely pressed together, re- 

 fract the light more strongly on account 

 of their containing a greater quantity of 

 solid matter, and present a more homogeneous appear- 

 ance. 



This kind of inspissation is by no means so rare a pro- 

 cess as it is often assumed to be, but on the contrary of 

 extremely frequent occurrence, and almost even more 

 important than frequent. This is namely one of the pro- 

 cesses which lead to the formation of the much discussed 



Fig. 64. Inspissated, cheesy pus. a. Shrivelled pus-corpuscles, diminished in 

 size, somewhat distorted, and looking more homogeneous and solid than usual. 

 b. Similar corpuscles with fat granules, c. Their natural position with regard to 

 one another. 300 diameters. 



