New YorK AGRICULTURAL EXPERIMENT STATION. 81 
Again there is a marked difference in the germ content of 
the milk received into the two sides of the pail and this differ- 
ence is very pronounced both with and without the presence 
of the filters. 
Contrasting either side of the pail when it is run with and 
without the filters it is seen that the presence of the filters re- 
sulted in a marked reduction in the germ content. This is par- 
ticularly marked on the side under the main suction filter 
where the averages were 19,856 per cc. when the cotton was 
placed in the filter cups and 51,600 per cc. where the cotton 
was omitted from the machine. 
Inefficiency of the small suction filter.— A possible explana- 
tion of the observed differences in the germ content of the 
milk from opposite sides of the pail might be the germ content 
of the respective cows’ udders. . However, the uniformity of 
the difference in the product of three successive pairs of cows 
renders this explanation highly improbable. 
Carefully secured samples of the last milk from the udders 
of these six cows were plated. The average germ content of 
those milked into the suction filter side of the machine was 
_ 556 per cc. while those milked into the opposite side of the 
machine had an average germ content of 1293 per cc. These 
differences are small and are in the opposite direction from 
the differences observed with the milking machine and there- 
fore do not aid in explaining these latter differences. 
An inspection of Plate V will show that the main suction 
filter is not placed in the center of the pail but at one side 
and over the part receiving the milk of one cow as indicated ° 
in Table V. When the milking of two cows has been com- 
pleted it was the custom to close the stanchion cock and dis- 
connect the stanchion hose at this point in order to admit air 
to the pail so that it could be opened. This sudden inrush of 
air through the four-foot stanchion hose carried with it such 
dust and bacteria as might be in this hose and in the air except 
as they were removed by the cotton in the main suction filter. 
