DESCRIPTIONS OF PATHOGENIC BACTERIA. 1 67 



mals they produce, according to their vir- 

 ulence, local suppuration, pyaemia or septi- 

 caemia. In man they have been observed in 

 abscesses and in inflammation of the bone- 

 marrow. The ability to induce suppuration is, 

 however, by no means limited to these microbes. 

 If cells of the body are destroyed mechani- 

 cally, or by poisons, the necrotic tissue thus 

 formed attracts the white blood-corpuscles. 

 These corpuscles are adapted to the task of keep- 

 ing free the circulatory channels and at the 

 same time they assist in the utilization of the 

 material fitted for resorption into the body. 

 Hence the wandering-out of the white blood- 

 corpuscles from the blood-vessels into the tis- 

 sues seems to be an important act of nutrition. 

 When, however, white blood corpuscles which 

 have been thus attracted come into the region 

 of bacterial poisons they are paralyzed by the 

 poisons, prevented from wandering back, and 

 become local pus-corpuscles. It is now known, 

 that, besides the pyogenic bacteria, other bac- 

 teria also can bring about pus formation, and 

 the same thing is true as well of bacterial 

 poisons and of other poisons such as corrosive 

 sublimate. 



In cases of severe suppuration the so-called 

 Streptococcus pyogenes or erysipelatos is the one 

 most commonly found. It is a coccus form 



