PARASITIC BACTERIA. 



137 



growth. It may become localized in a small 

 gland, a single joint, a small spot in the lungs, or 

 in the glands of the mesentery, the other parts 

 of the body remaining free from infection. Not 

 infrequently the whole trouble is thus confined 



flG. 31. Tuberculosis bacillus: a, As seen in lung tissue ; b, 

 More magnified ; c, As sometimes seen in sputum of con- 

 sumptive patients. 



to such a small locality that nothing serious re- 

 sults. But in other instances the bacilli may after 

 a time slowly or rapidly distribute themselves 

 from these centres, attacking more and more of 

 the body until perhaps fatal results follow in the 

 end. This disease is therefore commonly of very 

 slow progress. 



Again, we have still other parasites which are 

 not thus confined, but which, as soon as they 

 enter the body, produce a general infection, at- 

 tacking the blood and perhaps nearly all tissues 

 simultaneously. The most typical example of 

 this sort is anthrax or malignant pustule, a disease 

 fortunately rare in man (Fig. 32). Here the 

 bacilli multiply in the blood, and very soon a 

 general and fatal infection of the whole body 

 arises, resulting from the abundance of the ba- 



