252 



Subject Index. 



Bacillus coli, Continued 

 in lakes and streams, 130. 

 in Lawrence filter effluent, 134. 

 in Merrimac River, 134. 

 in nature, 114. 

 in polluted waters, 124, 128. 

 in Potomac River, 135. 

 in river waters, 126. 

 in sewage, 185. 

 in soils, 123. 

 in spring waters, 132. 

 in surface waters, 130. 

 in Susquehanna River, 135. 

 in Thames, 131, 

 in unpolluted waters, 124, 128. 

 in Washington filter effluent, 



135- 



in water supplies, 115, 117. 



in wells, 132, 133. 



isolation of, 98. 



isolation of, by litmus-lactose- 

 agar, 97. 



mo tili ty of, 104. 



on plants, 118. 



overgrowth by streptococci, 129. 



pathogenicity of, 116, 117. 



preliminary enrichment for, 89. 



presumptive tests for, 141. 



ratio of, to total bacteria in sur- 

 face waters, 129. 



removal in pipes and reservoirs, 

 136. 



significance of, 112. 



typical, i pi. 



variation in behavior, no. 

 B. communior, 88. 



dysenteriae, 80, 163. 



reactions of, 80. 



enteritidis, 163. 



enteritidis sporogenes, 161. 



Bacillus mycoides group, 99. 

 Bacillus sporogenes, 161. 



characteristics of, 162. 



occurrence in sewage, 162, 185. 



insolation of, 161. 



subtilis, 1 68. 

 Bacillus typhi, 163. 



comparison with B. coli, 78. 



positive isolations from water, 



80, 81. 



Bacteria, as agents of decompo- 

 sition, 3. 



as agents of purification, 184. 



counts of, at different tempera- 

 tures, 173. 



distribution, i. 



escaping detection, 25. 



factors in distribution, i. 



food requirements, 2. 



in Boston Harbor, 182. 



in contact beds, 193. 



in dust in air, 6. 



in effluents, 193, 194, 195. 



in effluents from sewage farms, 

 192. 



in humus, 3. 



in ocean, 14. 



in rain and snow, 6. 



in sandfilter effluents, 190. 



in sea water, 13. 



in septic effluents, 190. 



in sewage, 193. 



in soil, 3. 



in water, 5. 



in sand filter effluents, 190, 191. 



in wells, 52. 



in well water, 23, 24. 



metatrophic, 2. 



microscopic enumeration of, 25. 



number in lakes and ponds, 12. 



