102 STORRS AGRICULTURAL EXPERIMENT STATION. 
Underneath these groups we have tried to recognize the 
types of varieties which we have found and which are there- 
fore liable to be isolated from any samples of milk, and for the 
present we have grouped these as varieties A, B, C, D, etc., 
under the general name of the group. In this way we recog- 
nize the general classification of bacteria, and at the same time 
obtain an impression of the variations that develop within the 
types themselves. 
Method of Description.—In describing a long list of species of 
bacteria such as are included in the following pages, there are 
two different purposes to be considered, each of which would 
involve a different method of procedure. First, there is the 
question of dzagnoszs, which would call for such an arrange- 
ment of important characters as will enable other bacteriologists 
to identify forms which they may have in hand with those 
already described. There is, second, the need of such a com- 
plete description of the organisms in question, with a// its other 
characters as will finally and definitely describe them for a 
permanent record. In accordance with which of these two 
purposes we have in mind the method of description would be 
varied. 
In our own opinion at the present time the first of these two 
_.points is the more important. Until we know more about the 
general relations of bacteria, it is more important to have such 
a grouping of the types as will enable others to identify the 
cultures which they may have under observation with those 
already described. The more minute detailed description of 
species will undoubtedly of necessity come later. But when 
we recognize that such considerable variations of the same type 
are possible, and certainly do occur under cultural conditions, 
it becomes evident that the minute description of the physio- 
logical characters of the different cultures becomes of compara- 
tively little value. If the types are not constant in all of these 
points, it is certainly of no great value, at least in the present 
state of bacteriological science, to describe the particular char- 
acteristics of a culture at any particular time, especially if it is 
true that when cultivated in the laboratory for six months, 
these characters may largely change. Hence we have con- 
cluded that with the present state of bacteriological science the 
more valuable form of classification will be one which will 
