22 STORRS AGRICULTURAL EXPERIMENT STATION. 
produced. ‘The same is even more distinctly true of No. 208, 
for the organisms that we have in these experiments regarded 
as B. lactis aerogenes show variations too great to allow us to 
regard them as a single species. A more careful differentia- 
tion of this type of bacteria is to be undertaken in our labora- 
tory, but in these cream ripening experiments any further 
differentiation has been impossible. 
In addition to these there is in ripening cream a fifth group 
of bacteria which we have in general called Miscellaneous. 
They agree only in not producing acid. Commonly they pro- 
duce a solution with an alkaline reaction, although sometimes 
there is no reaction. Some of them liquefy the gelatin while 
others do not. They consist of quite a number of different 
species, comprising more varieties than the acid bacteria. 
From the tables it will be seen that the number of these 
miscellaneous bacteria is very small in ripened cream, a fact 
which led us to believe at first that they have little to do with 
the cream ripening, although later experiments have made us 
-doubt the correctness of this conclusion. 
Table 5 gives the results of experiments with cream from a | 
large creamery, extending from October to May, 1900, and 
two experiments in January, 1901. The results are expressed 
in percentages instead of in actual numbers of bacteria. 






ABLE SS, 
Percentages of chief types of bacteria in cream from a large 
creamery. 
IN UNRIPENED CREAM. | IN RIPENED CREAM. 
as 6 | SP] 3 Cais o 6.3 OSE. Ceetuaeeee 
late ree at # \z 
‘ ete wee et Se 
MEN 26: Nao. i Seb Pe 86 | 6a eho 
Wetuula, i. : 51.6)10.4| 1.9/64.3/35.7 63.6/35.6] .5199.7]. .3 
Oct 265. - 77.0/14.3] 3.5/94.8] 5.2 73.0|24.0] .7/97.7| 2.3 
WOVce25 25 - 71.0/23.0) 3.9|97.9) 2.1/77.5/19.0/1.1|97.6| 2.4 
Oct.430,.u- = 50.0/35.0/10.0/95.0] 5.0 55.0/41.0]2.5/98.5| 1.5 
March 23, - 44.0] 2,0} 6.0/50+|50—'88.0/10.0] ? |g8+]2 — 
May 4, - - 5220873 2.087.0/13.0 66.0/26.0 .2|}94.0| 6.0 
Jan. Ig, - - 33.0)/12.0| 7.0/52.0/48.0/77.0)17.0] .5/99.0| 1.0 
Jan. 28, - - ae 9.0 84.0/14.0 89.0 ? .2/91.0| 9.0 


















