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REPORT OF DAIRY BACTERIOLOGY. 15 
In this series of experiments the analysis of the bacteria was 
only a general one designed for detecting the chief types of 
milk bacteria, z. e. the per cent. of lactic organisms, of pepton- 
izing forms and of neutral forms; but no close attempt was 
made at obtaining an accurate analysis of individual species. 
The experiments, carried out under the direct work of Mr. 
Hsten, involved a more careful study of the species of bacteria, 
and the attempt was made to analyze the species present in 
milk very much more carefully. In this work we have deter- 
mined the species of bacteria present in the ordinary milk of 
our markets and so far as possible analyzed these bacteria to 
the distinct species. The work done along this line showed 
that the methods adopted were somewhat irregular and in a 
measure unreliable. This led toa long series of experiments 
to obtain methods of culture that are more uniform, and the 
experiments have resulted finally in the adoption of new culture 
media and new methods of using them. ‘The results of these 
experiments and the details of the methods now employed in the 
laboratory are also given below. 
In general the papers that are embodied in this report are a 
part of a series of studies upon the species of bacteria which are 
associated with and materially concerned in various dairy prob- 
lems. ‘They represent a continuation of experiments begun a 
year ago and are still in progress. 
Respectfully submitted, 
pit H. W. Conn. 
