120 SUPPURATION. 



corpuscles from the vessels. We must bear lu mind liowever 

 the following points of divergence : first, the path taken by 

 the migrating cells tends in the one case towards a free 

 surface, in the other, towards a point situated in the paren- 

 chyma of the connective tissue ; secondly, that in the develop- 

 ment of pus on mucous and serous membranes, the share 

 taken in its production by the epithelium must not be left out 

 of account. As regards the formation of pus in connective 

 tissue, i.e. the suppuration of an inflammatory exudation, with 

 which alone we are now^ concerned, we must keep in mind the 

 same reservations and restrictions which we were obliged to 

 establish in connexion wuth the process of plastic exudation 

 itself. It is by no means proved that all pus-corpuscles are 

 derived fi'om the vessels ; for on the one hand a formative irrita- 

 tion of the stationary corpuscles of connective tissue has been 

 shown to take place, and their break-up into migratory cells 

 rendered highly probable ; while on the other hand, multiplica- 

 tion of the exuded cells by division has been directly observed. 

 Finally, we may look on suppuration as in reality the most 

 direct continuation of the earliest phenomena of inflammation. 

 Its essential feature is a tendency towards over-production, 

 towards exuberance of o-rowth, wherebv colossal numbers of 

 young cells are generated in a relatively brief period of time. 

 The proximate cause of the suppuration of an inflammatory 

 exudation, or, in ordinary phrase, of the passage of inflammation 

 into suppuration, is often to be sought in the excessive afllux of 

 pabulum to the inflamed part ; hence the antiphlogistic method 

 of treatment endeavours in the first place to moderate or diminish 

 this afliux. In other cases again, we find the cause in the 

 quality of the irritant ; thus chemical agents, and particularly 

 septic ferments, lead to suppurative inflammations. Conversely, 

 we might anticipate that in indi^■iduals whose nutrient fluids 

 had undergone septic infection (septicaemia), every inflammation 

 would tend to assume a suppurative character. Finally, there 

 is such a thing as individual predisposition, i.e. there are 

 persons in whom the most gentle irritants excite suppurative 

 inflammations. But this is by the way. We must return to 

 the consideration of the anatomical course of the suppurative 

 process. 



^96. The next phase is the formation of an abscess. The 



