429 
ing term for 1906, and the average number of bacteria per cubic 
centimeter was cut in half. Convinced of the practical advantages 
of the bacteriological control of milk, one progressive dairyman in 
Washington has employed a competent bacteriologist to assist him 
in marketing a better quality of milk. 
One great advantage accruing from the bacteriological control of 
milk is that it affords an opportunity to exclude the milk of diseased 
cows. Cows frequently suffer with diseases of the udder; in fact, 
garget or mammitis is the most common of all bovine diseases. Milk 
from inflamed udders containing pus-producing organisms (strep- 
tococci) is believed by some to be more important than the pep- 
tonizing species, about which much has been said since the work of 
Fliigge. 
Fresh milk from cows with diseased udders contains an excessive 
number of streptococci and pus cells or an excess of pus cells alone. 
So far as we know, such milk is dangerous for infant feeding. While 
not all agree with this view, nor is there any agreement concerning 
what constitutes an excessive number of streptococci and pus cells in 
milk, the facts have been put to practical use by Jordan in Boston. 
There, milk “ infected” with excessive numbers of streptococci or -an 
excess of pus was traced back to the cow, with the result that thirty- 
one diseased cows supplying milk to Boston in 1906 were found and 
eliminated. Most of the animals had mammitis or garget; some had 
ulcerated teats, some had recently calved, and others were approach- 
ing the calving period, etc. a 
BACTERIAL COUNTS OF WASHINGTON MILK. 
METHODS. 
The number of bacteria found in any given sample of milk will 
vary with the methods used. It is not possible by any known 
method in bacteriology to determine the exact number of live bac- 
teria in a sample of milk. The counts obtained are always below 
the actual number present. This is due to a number of reasons. 
First of all the bacteria stick together in groups and clusters; some 
are held together by adhesive membranes in pairs, chains, or masses. 
It is therefore evident that a single colony on a plate may not rep- 
resent the growth from a single micro-organism. 
It is impossible to obtain a medium, temperature, and other condi- 
tions suitable to the requirements of all bacteria. Some grow best 
at high temperatures, others at low; some prefer acid, others alka- 
line media; some need oxygen, which is fatal to others, etc. 
a Thirty-fifth ann. rep. city of Boston, Health Dept., 1906. 
