14 MANUAL OF EQUINE MEDICINE. 



and the accumulated mass of cells moves to and fro with the 

 pulse. This is the stage of oscillation, and it is followed by 

 that of stasis, in which no movement of any kind takes place. 



Finally, thrombosis may occur, when the capillary walls 

 have lost all vitality. 



(2.) Escape of Fluid and of Blood-cells ffom the Vessels. 

 — Some of the leucocytes adhering to the sides of the vessels 

 gradually sink into the walls of the small veins, and (to a 

 less extent) of the capillaries, and pass through them. Eed 

 blood-cells also pass through, but to a far less extent. In 

 severe inflammation, however, where the stagnation in the 

 capillaries is extensive, red cells may pass through almost 

 alone, and in large numbers, thus giving the exudation an 

 hsemorrhagic character. The red cells pass out chiefly from 

 the capillaries ; the intensity of the inflammation and the 

 vascularity of the tissues determining the proportion of them 

 in the exudation. 



The red and white cells at first remain near the vessels 

 from which they have escaped, but are soon washed away by 

 the exuding fluid, and the white cells move, in addition, by 

 their own peculiar power of locomotion. • 



It is almost certain that all new cells formed in inflamed 

 tissues, as a direct result of the injury which caused the pro- 

 cess, are escaped hlood- cells. 



In the less acute forms of inflammation, cells are also 

 formed by regenerative processes going on in the cells of the 

 tissues ; but these are not of inflammatory origin. The com- 

 position of inflammatory exudation is not constant. In the 

 most acute inflammations it contains very many red cells; but 

 in the less severe forms, white cells are in excess of the red. 



The more severe the process, the more does the exudation 

 resemble plasma in composition and character ; while in the 

 less severe forms it becomes more like the fluid exuded in 

 mechanical hypertemia. 



