I4 2 THE STORY OF GERM LIFE. 



certain. Still, the studies of the last twenty years 

 or more have disclosed some definite relations of 

 bacteria and disease, and a list of the diseases 

 more or less definitely associated with distinct 

 species of bacteria is of interest. Such a list, 

 including only well-known diseases, is as follows : 



Various wound infections, including septic&mia, 

 py&mia, acute abscesses, ulcers, erysipelas, etc., are pro- 

 duced by a few forms of micrococci, resembling 

 each other in many points but differing slightly. 

 They are found almost indiscriminately in any of 

 these wound infections, and none of them appears 

 to have any definite relation to any special form 

 of disease unless it be the micrococcus of erysip- 

 elas. The common pus micrococci are grouped 

 under three species, Staphylococcus pyogenes an r ens, 

 Staphylococcus pyogenes, and Streptococcus pyogenes. 

 These three are the most common, but others are 

 occasionally found. 



In addition to these, which may be regarded as 

 demonstrated, the following diseases are with 

 more or less certainty regarded as caused by dis- 

 tinct specific bacteria: Bronchitis, endocarditis, 



