CHAPTER IV. 

 SUBFAMILIES AND GENERA OF THE COCCACEiE. 



The application of the tests enumerated in the last 

 chapter, to five hundred cultures of cocci, gave eleven 

 more or less definite facts in regard to each culture. 

 The records were then analyzed to find the centers of 

 variation for each character and to determine what 

 characters were mutually correlated. The detailed 

 analysis of the figures has been published elsewhere 

 (Winslow and Rogers, 1906), and need not be repeated 

 here. 



The first result of a study of the correlated characters 

 of the five hundred cultures was the conclusion that the 

 division of the Coccaceae into a parasitic and a saprophy- 

 tic subfamily is amply justified, altho the characters by 

 which we originally defined these subfamilies require 

 modification and extension. Of the 500 strains studied, 

 59 had been isolated from diseased conditions and 170 

 from the normal human body, making a total of 229 from 

 a parasitic habitat; 95 were from water, 67 from earth, 

 and 109 from air, a total of 271 from saprophytic environ- 

 ments. Obviously such a distinction cannot be abso- 

 lute. Cocci get on the skin and into the alimentary tract 

 from various sources ; and parasitic forms occur in water, 



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