222 DISEASES FROM HARMFUL ORGANISMS 



Pus-forming Organisms. — There are several kinds of 

 bacteria (Fig. 56) that establish themselves ordinarily 

 just below the outer surface of the skin or in correspond- 

 ingly exposed positions within the mouth or other pas- 

 sages of the body. These organisms are called pus- 

 formers, because the dead bodies of the organisms become 

 mixed with white corpuscles and a certain amount of 

 fluid to form pus. Ordinary pimples and boils are familiar 

 results of the establishment of pus-forming organisms 

 just under the skin. Most of the pus- forming organisms 

 produce poisons which pass from the infected spot into 



Fio. FiCi. — One Typo of Pua-Forming Organism (Strcptococcufl). 



the body fluids and so are distributed about the body. 

 Certain of these organisms produce very violent poisons 

 and give rise to the condition formerly known as " blood- 

 poisoning." 



Pus-pockets. — The common sorts of pus-formers pro- 

 duce a relatively mild poison and the body in which they 

 are present is referred to as having a low-grade infection. 

 It has long been known that in certain regions, particu- 

 larly around the roots of the teeth and in the tonsils, low- 

 grade infections of this type may become established and 

 continue for years. The typical course of events is for 

 the organisms to live along, month in and month out, 

 multiplying only as fast as they die, and so not increasing 

 in numbers, producing only small amounts of pus and 



