Inflammation. Phlogosis. Phlegmasia. 49 



toxin), and digestive ferment (enzyme) of the leucocytes are 

 more deadly to the invading germ, than its ptomaines, toxins and 

 enzymes are to the leucocyte, the white cell comes off the victor, 

 and recovery takes place, but if the converse obtains the triumph 

 is on the side of the microbe. As a rule much depends on the 

 more or less deadly nature of the products of the invading mi- 

 crobe, on the numbers of the germ, the rapidity of its prolifera- 

 tion, and the consequent amount of its toxic products thrown into 

 the system, on the one hand : And on the other the potency of 

 the chemiotaxis of the leucocyte for the invading germ, the num- 

 ber of white cells that emigrate into the inflamed tissue and en- 

 gage in the work of phagocytosis, and on whether the particular 

 animal system and its white cells have sustained a previous at- 

 tack by the same germ and has thereby been educated to produce 

 a greater amount of the defensive proteids (leucomaine, anti- 

 toxin, enzyme) than it naturally would (acquired immunity). 



Even with an abundant emigration of the leucocytes into the 

 inflamed or invaded tissue, a number, greater or less, are usually 

 destroyed by the bacterial poisons and pass into degeneration or 

 liquefaction, as in the formation of pus, and yet the attacking 

 germ may be overcome, destroyed and devoured by the rapidly 

 increasing survivors. In general terms the migration of the cells 

 is in inverse ratio to the susceptibility of the animal to the mi- 

 crobe or the disease which it causes. 



The positive and negative chemiotaxis, which determine phago- 

 cytosis or prevent it, may be seen in the action of the leucocytes 

 toward the germs of two diseases, to one of which the animal is 

 susceptible and to the other of which it is not. Thus the leuco- 

 cytes of the pigeon take in the bacillus anthracis and suffer noth- 

 ing apparently, whereas the same white cells of the dove are re^ 

 pelled by the bacteria of fowl cholera which are not therefore 

 found in their interior. 



The leucocytes that migrate from the bloodvessels are in the 

 main, the most numerous, (the neutrophile or polynuclear) form ; 

 the mononuclear leucocytes with horseshoe shaped nucleus also 

 migrate but in much fewer numbers arid are as a rule less oc- 

 cupied in phagocytosis. At the same time, these two forms may 

 show each a preference for a particular microbe, the polynuclear 

 cell sometimes devouring one which the mononuclear cell rejects, 



4 



