122 Report OF DEPARTMENT OF BACTERIOLOGY OF THE 
It will be seen from this table that the determinations of 
fermentative ability extended from 1902 to 1906, but that the 
larger amount of work on this phase of the subject was done 
in 1904 and 1905. Under laboratories, V and N refer to the 
Vermont and New York laboratories respectively. Under ob- 
servers, M and H refer to the authors while S and P indicate 
that the actual manipulations of the determinations were done 
by L. P. Sprague or M. J. Prucha, assistants at the two labo- 
ratories. These tests were made under the immediate super- 
vision of the authors, and the results were, for the most part, 
personally inspected. by them, and they accept the -responsi- 
bility for their accuracy. | 
Under group number is given the group number which 
would result from the particular determinations in question 
and an inspection of this heading under each organism brings 
out sharply the variations observed. 
It should be remembered that each of the 550 determina- 
tions of fermentative ability recorded in the above table was 
conducted almost exclusively in triplicate, a comparatively 
small number having been made in duplicate so that this 
table really summarizes the results from approximately 1,500 
fermentation tube cultures. It occasionally happens that in 
a fermentation test in triplicate, gas will not appear in one 
or more of the tubes and this is especially liable to happen 
where the total amount of gas is small, as in the case of this 
group of organisms. A complete record of these discordant 
results was kept at the Vermont laboratory and the cases 
are indicated in the table by +. The total number of these 
cases observed at the Vermont laboratory was 23. At the 
New York laboratory where the card system of note keeping 
was being tried in various forms the record on the card was 
made on the basis of the triplicate test rather than that of 
the individual fermentation tube and the exact number of 
these variations is not known, but they were probably not 
greater than those given for the Vermont laboratory. 
In the fermentation tubes which were used the closed arm 
has a capacity of 10 cc. In all but a few cases the gas pro- 
duced had a volume of 1 cc. or less and accordingly was re- 
