REPORT OF THE DIRECTOR. 9 
Bulletins of the Station. With the progress of the inquiries 
and the increase in the number of species isolated, it has been 
found necessary to devise a method of classification in order to 
make it easier to determine whether any particular organism 
which may be isolated is identical with some one already found 
or is a new species. In the present Report Prof. Conn dis- 
cusses a method which he has developed for use in his own 
laboratory, and classifies according to it the species which he 
has isolated there. This method of classification has proved 
so useful that Prof. Conn has given it herewith in considerable 
detail, in the hope that it may prove useful in establishing a 
means by which American bacteriologists can compare their 
results. 
BOVINE TUBERCULOSIS. 
The experiments with tuberculous cows and with their milk 
for feeding calves, which were begun in 1896, have been con- 
tinued during the past year. The present Report gives a 
statement concerning the condition of the cows and details of 
the experiments for the year 1899. These studies are being 
continued. 
ANALYSIS OF FOODS, FEEDING STUFFS, ETC. 
_ In connection with the inquiries of the Station a large num- 
ber of chemical analyses are required. During the past year 
_ these have included analyses of samples of crops grown in the 
tests with fertilizers, and of foods and other materials used in 
the metabolism experiments with man. 
In addition to the chemical analyses of the various foods, 
feeding stuffs, etc., the heats of combustion of these materials, 
which are used in determining their fuel values, have been 
determined by the use of the bomb calorimeter. 
FOOD AND NUTRITION OF MAN. 
Investigations upon human nutrition have been carried on 
during the past year as usual. These are conducted in coop- 
eration with the U. S. Department of Agriculture, which 
defrays a considerable share of the expense. In this way 
much more extensive and accurate inquiries are made than 
would otherwise be possible. The lines of research during the 
past year have been chiefly metabolism experiments with a 
