Inflammation and Fever. 9 



Infljainmatory New Formations. Of the growths in 

 lymph tliere are two principal kinds : first, the plastic, 

 fl^rinous, granular, or molecular / and second, the aplastic, 

 croupous, or corpuscular. The first form tends to develop 

 inLo new structure, the second lo disintegrate and decay. 

 TLe tendency to one or other form depends largely on tlie 

 strength or weakness of the system's health, on the deficiency 

 or excess of corpuscles in the exuded fluid, and on the dis- 

 tance of the latter from living tissues and blood-supply. 

 Much also depends on the predisposition of the genus, the 

 tendency to suppuration in lymph being in a descending 

 series from liorse, ass, and mule, through ox and sheep, to 

 dog, pig, and, finally, the bird, in which latter suppuration 

 is quite exceptional. 



Suppuration. In inflammations of a high type, in those 

 occurring on the skin or mucous membranes in whicli there 

 is an extraordinary increase of nuclei and embryonal cells, 

 and in lymph thrown out in excess at one point, so that its 

 central parts are far from vascular tissue, the cell elements 

 undergo a rapid increase and degradation into pus-corpuscles, 

 and its solidified intercellular lymph undergoes granular 

 decay and liquefaction into the liquid of pus. 



While the above conditions are favorable to the forma- 

 tion of pus, the process of suppuration must now be recog- 

 nized as an infective process due to the propagation of bac- 

 teria (mainly chain forms — Streptococcus pyogenes — and 

 cluster-groups — Staphylococcus pyogenes). These or other 

 bacteria are found in the pus of acute abscesses, and when 

 absent in chronic abscesses are to be considered as having 

 perished since the abscess was recent and active. Inoc\ila- 

 tion of a rabbit with an excess of the pus of an acute abscess 

 produces general purulent infection (pyaemia) and early 

 death ; from a medium dose an abscess is produced ; while 

 from a small dose tliei'e is no effect whatever. In the latter 

 case the bacteria are overcome and devoured by the abun- 



