CLASSIFICATION OF DAIRV BACTERIA. 21 
it dificult to define it with accuracy, I have simply retained 
the original number by which this species has been entered in 
my laboratory notes. It is hoped that further study in future 
years may enable me to determine more accurately whether the 
species should be subsequently kept isolated and given specific 
names or whether they may eventually be merged into some of 
the other more common types. 
METHOD OF TABULATION. 
In the use of the tables the following methods have been 
adopted. At the top of the table in parallel columns are given 
certain characteristics which are indicated for each organism in 
the proper column by the sign + or —. The sign + indicates 
always that the species possesses the characteristic in question, 
the sign — that it does not possess the characteristic in question. 
In some places the sign + has been inserted, which indicates 
that the characteristic in question is doubtful. For example, 
under the column headed ‘‘ Diameter greater than 1p’’ the + 
means the diameter is practically 14. In the column referring 
to the reaction of milk, the + sign indicates that the reaction 
is unchanged or is amphoteric. ‘The other places where the 
-— sign is used explain themselves. In the use of this table 
the word bacillus merely refers to the fact that the organism 
is a rod rather than a coccus, and it does not mean that the 
organism is a bacillus in the sense of Migula’s classification. 
The tables when thus filled out give in a brief compass the 
chief diagnostic characters of the different species of bacteria. 
But these are not sufficient to give a complete description. 
There is therefore given in the pages following the table, under 
the proper numbers and names, such description of diagnostic 
characters as may be needed, in addition to those inserted in 
the tables, for the proper diagnosis of the species. By the use 
of the tables and these descriptions together each species is 
described as fully as possible from the data which are in my. 
possession. ‘These tables will be found extremely simple to 
use if one has a species of bacterium which he wishes to iden- 
tify with those described. My method is as follows: I make 
a ‘“trial slip’? giving the characters included in the tables. 
Upon this slip I enter the characteristics of the species being 
studied with the + and — signs in spaces corresponding to 
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