136 



EXCREMENTAL ORGANISMS 



devoted more attention to these estimations than their Ameri- 

 can confreres, but neither have studied them as fully as they 

 deserve and it is to be hoped that this condition will soon be 

 rectified. 



These organisms will now be treated in detail. 



1. B. Coll. The term B. coU in these pages is used to 

 signify the general group of aerobic, non-sporulating organisms 

 that ferment lactose with the production of acid and gas, and 

 not one particular member of the group, such as B. coU com- 

 munis, having certain specific characteristics in addition to the 

 generic ones just described. Many attempts have been made 

 to regard certain members of this group as being more sig- 

 nificant than others-but this has been a comparative failure 

 when viewed by the light of later experience. 



MacConkey ^ reported upon the biochemical characters of a 

 number of members of the B. coli group, isolated from milk and 

 from the faeces of cows, and classified them into four groups 

 according to their action on saccharose and dulcite. The 

 results are given in Table LIV. 



Table LIV 



Saccharose +dulcite + 

 Saccharose — dulcite + 

 Saccharose +dulcite — 

 Saccharose —dulcite— 



MacConkey suggested that these groups should be further 

 subdivided according to the abihty to ferment adonite and 

 inulin, the Voges and Proskauer reaction, and the motility. 

 In 1909 he reported the characteristics of colon organisms 

 isolated from animal and human faeces and arranged the group- 

 ing in accordance with the subdi vision. ^ As this further 

 division has not been generally adopted, the results have been 



