112 REPORT OF DEPARTMENT OF BACTERIOLOGY OF THE 
The above table presents as concisely as possible the results 
of observations made under 38 headings. These observations 
were made upon an average of 25 cultures for each of the 45 
germs which were studied, or an average of approximately 
1,000 cultures for each heading. Owing to the fact that a 
single culture would furnish the information given under a 
number of headings, only about 12,000 cultures are actually 
represented in this table, although some thousand additional 
were required in the preliminary cultivations and in the 
revivifying process. 
While the above results are perfectly accordant in all of the 
items covered by + and — it would be misleading to assume 
that no apparently discordant observations were made. Every 
item was determined a number of times, usually in triplicate, 
and in practically all cases these determinations were made 
in both laboratories, the more important of them having been 
determined independently by four different workers. 
The importance of revivified cultures has already been em- 
phasized and it was in the determinations which were made 
previous to the application of this preliminary cultivation that 
the larger part of the variation was encountered. However, 
revivication does not remove all of the tendency to vary which 
is resident in some of the cultures. 
In summarizing in the table the results which were not 
entirely accordant the rule has been followed that a single 
well-marked positive result was more important than a number 
of negative ones. Wherever a single positive result was 
marked as doubtful for any reason and the other observations 
were uniformly negative the test has been recorded as negative 
in the table, but attention will be called to such cases in the 
following remarks. 
Pellicle on broth. The pellicle on broth is usually thin and 
in many of the earlier observations it was recorded as absent. 
Careful observations on cultures which had not been disturbed 
showed that the pellicle begins with the formation of floating 
masses of pseudozooglea which are gradually united into a 
delicate film. If the culture is even gently shaken these sink 
