Body Temperature Organisms. 65 



shows an even sharper differentiation than that at 40 

 degrees. Gage rightly concludes that "the information 

 to be obtained by counts of bacteria and acid-producing 

 organisms at any one of the above temperatures is greatly 

 increased by the combination of the results obtained from 

 counts at two or more temperatures. " 



In warm weather the interpretation of the body tempera- 

 ture count must be made less rigid than at other seasons. 

 Recent investigations have shown that in midsummer 

 bacteria capable of growth at 37 degrees are more abun- 

 dant in normal waters than in winter and spring. 



Winslow and Phelps (in a recent unpublished study) 

 examined 86 samples from springs, wells, brooks and 

 pools during the winter and spring months and found only 

 12 which showed more than 25 bacteria per c.c. and only 

 3 which showed mo're than 100 per c.c. on lactose-agar. 

 On the other hand, of 58 samples from , corresponding 

 sources examined in summer, 16 contained more than 100 

 bacteria per c.c. A series of 20 pools, ponds and brooks 

 at Mt. Desert, Maine, which were entirely free from 

 human or animal pollution, were examined in the late 

 summer of 1906. Only four of the 20 samples gave 

 counts under 25 at 37 degrees, and seven of them gave 

 counts over 100, the highest figure being 425. Similarly 

 it has been pointed out that in tropical countries organisms 

 capable of development at 37 degrees may thrive abun- 

 dantly in normal waters. 



A majority of the English Committee appointed to 



