i 7 6 



C.-E. A. WINSLOW AND ANNE F. ROGERS 



In examining Tables 4 and 5, which show the fermentative power 

 of dextrose and lactose broth, the fundamental difference between the 

 parasitic and saprophytic cocci is again made evident. In the first 

 two groups, from the animal body, over two-thirds of the cultures 

 produce more than 0.3 per cent of normal acid; while among the 

 earth and water forms two-thirds of the organisms form less than this 

 amount. With lactose the same law holds. Two-thirds of the cocci 

 from the normal body produce acid in lactose, against less than 

 one-third of the water and earth forms. The air cultures show an 

 intermediate relation. 



TABLE 6. 

 CORRELATION BETWEEN HABITAT AND REDUCTION OF NITRATES. 



The property of nitrate reduction does not appear to be related 

 to habitat in any such direct way as the other characters studied. 

 The air cocci, however, show a peculiarity of considerable interest, 

 nitrite formation being common, and ammonia formation very com- 

 mon, among them. 



TABLE 7 . 



CORRELATION BETWEEN HABITAT AND OPTIMUM TEMPERATURE FOR GROWTH. 



While a majority of the cultures studied grow indifferently at 20 

 or 37, it appears from Table 7 that among the parasitic forms a 

 fair proportion are favored by the body temperature, while more 

 of the earth and water forms develop best at 20. With regard to 

 the optimum temperature for color formation, no definite relation 

 with habitat appears, except as involved in the double relation between 

 chromogenesis and habitat, and chromogenesis and the optimum 

 temperature for color formation. These figures are therefore 

 omitted. 



