144 PATHOLOGY 



Cicatrix or Scar. The replacement of tissue destroyed 

 by inflammation or otherwise by a peculiar form of 

 connective tissue, called scar tissue, is called cicatriza- 

 tion, and the result is called a scar or cicatrix. 



Suppuration. This is an inflammatory condition in 

 which necrotic tissue and inflammatory exudate are 

 liquefied by the action of pyogenic micro-organisms. 



Pus. The liquid resulting from the process of sup- 

 puration is called pus. It is composed of white blood- 

 corpuscles, broken-down tissue cells, serum, bacteria, 

 etc. 



Abscess. When a circumscribed area of suppuration 

 occurs within the substance of a tissue or an organ, the 

 lesion is termed an abscess. An abscess may, therefore, 

 be defined as a circumscribed collection of pus sur- 

 rounded by a restraining wall of proliferative tissue, 

 which has been referred to as "the pyogenic membrane," 

 from the mistaken idea that it was concerned in the 

 production of the contents of the abscess. 



Diffuse Cellulitis or Purulent Infiltration. When 

 suppuration within a tissue or organ does not become 

 circumscribed, but spreads through the substance of the 

 tissue or organ, the condition is known as diffuse cellu- 

 litis or purulent infiltration. This condition is usually 

 due to streptococcus infection. 



Ulcer. Suppurative conditions upon the surface of 

 an organ or tissue (i. e., upon the skin or mucous mem- 

 branes) give rise to erosions termed ulcers. An ulcer 



