MILK AFFECTED BY DAIRY PRACTICES. 87 
Diagram showing the above averages in graphic form. 
Students, 
# 
Regular men, 
Difference, 
than nine times as many bacteria as did that drawn by the 
student, while the average of the five comparisons shows that 
the milk drawn by the students contained but one-third as 
many bacteria as that drawn by the regular men. ‘These aver- 
age differences are brought out by the diagram in connection 
with Table No. 28. All of the stable conditions were, of course, 
the same for both and the difference in results must be attributed 
to the difference in care exercised by the individual men. 
In Table No. 29 are given the results of a series of compari- 
sons between the same two men mentioned above and a grad- 
uate of the College who was at the time in charge of the dairy 
herd. In each case five cows were milked by him and the milk 
compared with that from five cows milked by the two men. 
These results are even more striking than those given in the 
preceding table. The men all had the same instructions in 
regard to cleaning the udder and followed the same methods of 
milking but the one uniformly obtained milk with a low germ 
content while the others obtained milk with several times the 
number of bacteria per cubic centimeter. In some cases the 
differences are extreme, as in experiments 7 and 8. ‘The av- 
erages for the nineteen experiments given here show that one 
man obtained milk containing 2,455 bacteria per cubic centi- 
meter, while under the same conditions the other men obtained 
milk with 17,100, or seven times the number of bacteria in the 
same quantity of milk. These relative values are strikingly 
illustrated by the diagram at the bottom of the table. These 
differences can be accounted for only by the difference in the 
individual care used in their work, by the different men. These 
results emphasize very strikingly the important part which the 
