[HARRISON-SAVAGE] BACTERIAL CONTENT OF THE UDDER 37 
Foremilk. 
After drawing a single stream of milk the flora remained as noted. 
The animal was not killed. 
PREDOMINANT SPECIES. 
These results point clearly to the flora of the udder being a small 
one, and, aside from the foremilk, which seems subject to a certain 
amount of change, show that it is practically limited to a few species 
of white and yellow cocci. The authors call attention to the predomin- 
ance of M. albidus and M. varians in the lists of organisms found, and 
particularly to the fact that these bacteria occurred in both virgin and 
mature udders. 
M. albidus was found in 3 out of 5 virgin udders. 
“ “ “ “ “ 4 SO MER 7 mature “ 
M. varians “ 4 A ge a LED £ 
“ “ “ “ “ 3 “ “ 7 mature “ 
In comparison with these, the other species encountered scarcely 
deserve comment. It is true that the number of udders examined was 
not large, but the results are endorsed in a general way by the experi- 
ments of Ward, Gorini, deFreudenreich, and others, and we conclude 
from these experiments that :— 
(a) the flora of the normal udder, as a whole, consists chiefly of 
yellow and white cocci. 
(b) the bacteria found in the region of the teat and milk-cistern, 
and which are ejected in the foremilk, are not necessarily typical of 
the entire flora of the gland. 
Means and Time of Entrance. We have stated that the freshly 
drawn milk may be divided into the foremilk and the rest. The bac- 
terial flora of the former may vary from day to day, but that of the latter, 
especially the strippings, remains practically constant. Such being 
the case, whence come the organism and how do they enter the gland? 
The milk in the teat and the milk cistern is influenced to some ex- 
tent by the surroundings of the cow, and although we cannot state that 
the animal exerts a selective action, yet, some organisms after gaining 
entrance to the udder increase in numbers whilst others do not, other- 
wise, the number of species found in the udder would be much larger, 
as deFreudenreich has already noted. Kitt, Harrison and Cumming, 
Ward, and others have shown that various organisms may invade the 
udder when cultures of them are smeared over the teat openings; on 
the other hand Guillebeau and Hess, and Steiger, have shown that other 
organisms cannot effect an entrance under similar conditions. The 
