SEA-FISHERIES LABORATORY. 



127 



of all the organisms studied. These, we may hold, are therefore 

 really distinct species, or at least small groups of such. Com- 

 paring this Table with that published by MacConkey we also 

 see that very much the same kinds of organisms have been 

 found in both cases. 



Group I, in my table, includes the species called, by 

 MacConkey, B. griinthal, B. sulcatus gasoformans, B. castellus, 

 and B. vesiculosus. The first three organisms differ from the 

 latter one only in that they are motile while it is not so. No. 2 

 in my table appears to correspond with the organisms numbered 

 100 and 101 by MacConkey. No. 3, called B. acidi lactici, is 

 very rare in MacConkey's list. B. coli communis and B. 

 cavicida are much more abundant in MacConkey's list than in 

 mine. Many of the other unnamed organisms may be found 

 in both lists. The two groups of organisms may best be 

 compared as follows : — 



MacConkey. Organisms 



abundant in human 



faeces. 



B. neapolitanus 



B. No. 71 



30% 



Organisms present 



in Sewage polluted 



Mussels. 



4% 



B. vesiculosus 



B. griinthal 



B. sulcatus gasoformans 

 B. castellus 



B. coli communis 



B. cavicida 



22% 24% 



20% 



B. schafferi 6% 



B. lactis aerogenes ) 



B. dysenteriae I 4 % 



B. capsulatus ) 



Organisms rare in 

 human faeces. 



B. acidi lactici 0-5 % 



B. coscoroba 0-5% 



B. cloacae 00% 



B. Nos. 100 and 101 



0,5 % 



7% 



o% 



6% 



9% 



2% 



o% 



10% 



B. rhinoscleroma 0-5 % 1 % 



Thus we see at once that the organisms which appear 

 normally to inhabit human faeces, and those which may be 

 I 



