1 64 SUPPURATION AND ALLIED CONDITIONS. 



organised being affected first; and (c) a liquefaction or 

 digestion of the supporting elements of the tissue. Any 

 previously- formed fibrin is also softened and disappears. 

 The result is that the solid tissue becomes replaced by the 

 cream-like fluid called pus, a fluid which does not coagulate, 

 and in which the chief cellular elements are polymorpho- 

 nuclear leucocytes, along with the degenerated cells of the 

 part. Suppuration is therefore to be distinguished, on the 

 one hand, from a severe inflammation, in which, however, 

 the tissue is not destroyed, and on the other hand, from 

 necrosis or death of the tissue en masse. When, however, 

 suppuration is taking place in a very dense fibrous tissue, 

 liquefaction may be incomplete, and a portion of dead tissue 

 or slough may remain in the centre, as is the case in boils. 

 In the case of suppuration in a serous cavity the two chief 

 factors are the progressive leucocytic accumulation and the 

 disappearance of any fibrin which may be present. 



The liquefaction of the formed tissue elements in sup- 

 puration is believed to depend chiefly upon a peptonising 

 action of the organisms or of ferments produced by them, 

 and the progressive leucocytic aggregation is most probably 

 the effect of microbic products which attract the leucocytes, 

 or in other words exert a positive chemiotaxis. We might 

 expect that any organisms which could flourish in the tissues 

 and exert these actions would produce suppuration, and as 

 a matter of fact a considerable number have been found to 

 possess pyogenic properties. 



The terms scptic&mia and pycemia may be first explained, 

 as these will be frequently used. Septicaemia is applied 

 to conditions in which the organisms multiply within the 

 blood and give rise to symptoms of general poisoning, 

 without, however, producing abscesses in the organs. It is 

 to be distinguished from conditions in which there is a 

 merely local growth of bacteria, the symptoms being pro- 

 duced by absorption of their toxines. In all cases of 

 septicaemia the organisms are more numerous in the 

 capillaries of certain organs than in the peripheral circula- 

 tion, and, in the case of the human subject, it is usually 



