C.-E. A. WINSLOW 69 



enon familiar to us in our culture media and in such substrata as soil or milk. It was 

 noted in water by Cramer as early as 1885 in the following very clear example. Lake 

 Zurich water stored for a period of seventy days: 



Storage Period, Days Numbers per Cc 



o 143 



1 12,457 



3 328,543 



8 233,452 



17 17.436 



70 2 , 500 



A much less marked but fundamentally similar cycle is given by Conn (1918) for 

 the change of bacterial numbers in freshly manured soil. 



Storage Period, Days Numbers per Gram 



o 35, 000 , 000 



I 120, 000 , 000 



2 100 , 000 , 000 



3 145 ,000,000 



4 150, 000 , 000 



6 120, 000 , 000 



9 70 , 000 , 000 



16 70 , 000 , 000 



60 75 , 000 , 000 



120 23,000,000 



Jordan (1926), in one of his experiments on stored feces, noted that, taking the 

 initial number of bacteria present as 100, the relative number rose during storage to 

 between 2,000 and 3,000 on the fifth to the ninth day and then fell to about 1,000 on 

 the eleventh day and to less than 400 on the twenty-first day. For colon-group or- 

 ganisms under similar conditions he gave the following results: 



COLON BACILLI IN FECES STORED AT ROOM TEMPERATURES 

 Relative Numbers Considering Initial Number as 100 



Storage Period, Days Relative Numbers 



3 7 , 000 



5 3.730 



7 3 , 600 



9 2 , 400 



II 930 



14 530 



16 24 



18 26 



21 24 



23 14 



The curves in Figure 3 plotted from averaged results given by Prescott and Baker 

 (1904) for the numbers of colon bacilli and streptococci developing in glucose broth 

 inoculated with polluted water and incubated at 37° C. illustrate the difference in the 



