404 
THOMPSON YATES LABORATORIES REPORT 
It is rather remarkable that serum A should have had so marked an effect on 
B. coli. The readiness with which the latter bacillus is agglutinated is, however, well 
recognized ; unfortunately, the serum had not been tested with B. coli before the 
guinea-pig was inoculated with Bacillus ' L.' Serum A evidently had very little 
influence upon B. typhosus or the two members of the B. enteritidis group. 
Identification of Bacillus ' L ' 
From the cultural relationships described above, it seems justifiable to put 
Bacillus ' L' into the B. enteritidis group, in spite of the divergence of its reaction 
in milk. This seems the more reasonable when it is remembered that milk cultures 
of the B. typhosus group are not uniform, some becoming alkaline after a week or 
more of incubation, whereas the typical group reaction in milk is acid. 
Of the bacilli described by Kruse in Plugge's Micro-organismen, there are four 
with which Bacillus 'L' is comparable : B. icterogenes, B. paradoxus, B. monadi- 
formis, and B. chologenes. The statement 'does not coagulate milk,' made with 
regard to the first three of these, does not give information as to whether or not these 
organisms render milk alkaline. However, Bacillus 'L' is differentiable from the 
first, third, and fourth, in that the latter ferment lactose ; from the second, because 
of the latter's close resemblance to B. typhosus on potato. 
Bacillus No. 32. in Germano and Maurea's 12 elaborate table is the only one 
found recorded with which Bacillus 'L' may be said to agree culturally; even in 
this case it is not stated by the writers whether or not milk was rendered alkaline. 
In view of the aetiological relationship of Bacillus ' L' described in the present paper, 
it is not unlikely that Germano and Maurea's No. 32 was the infective agent in 
the supposed case of typhoid from which it was isolated ; but that was before the 
days of the serum-reaction. 
This study has fully confirmed the opinion expressed by Cushing 5 that whether 
the cultural characteristics of the B. enteritidis group are but temporarily acquired 
and their intermediate existence merely transient, may be a question of dispute ; but 
that nevertheless the definiteness of their serum-reactions, their pathogenicity, and 
the constancy of their cultural features justify placing them in a separate group. 
It may not be out of place to draw special attention to the papers by Cushing 5 and 
Durham 9 which have been freely consulted during the present study ; the former 
illustrating the possibilities of a complete study of a group of organisms ; the latter 
combining theoretical suggestiveness with a useful working classification of the groups 
under discussion. 
