908 The American Naturalist. [November, 
If the butter-maker owes something to bacteria the cheese- 
maker owes everything to them, The butter-maker cannot 
get the proper aroma without the agency of bacteria, but the 
cheese-maker cannot get anything. Of course, you all know 
that fresh cheese is very inane and tasteless. Nobody likes fresh | 
cheese. It has sort of a curdy taste and is quite unpalatable. 
You know, however, that after cheese is made it is set aside 
for a number of weeks to ripen. It may ripen several weeks, 
or, perhaps, months. Sometimes in the case of the best 
cheeses it may be ripened a year or more. Now during that 
ripening process exactly the same changes are taking place 
that I have mentioned in cream. The bacteria are growing, 
are attacking the casein, and pulling it to pieces. They pro- 
duce many changes in it and cause an accumulation of all 
sorts of materials which have peculiar tastes, and little by lit- 
tle the cheese is ripened. After a while the cheese begins to 
have a pleasant taste and then a strong taste, and if you leave 
it long enough you get a very strong cheese. The longer you — 
ripen a cheese the stronger its taste becomes. An old cheese 
is always a strong cheese, a fresh cheese is always a mild 
cheese. The shorter the time you cultivate bacteria in it of 
course the slighter will be the changes which they produce; 
the ionger you cultivate the bacteria the stronger becomes the 
cheese. 
Now in the ripening of cheese we find the cheese manufac- 
turer’s greatest difficulty. Every cheese manufacturer knows 
that under conditions which seem to be exactly alike he may 
get good cheese and he may get bad cheese. His cheese may 
become tainted, it may become spotted with little red spots or 
some other abnormal conditions may appear which he cannot 
account for. It would be the greatest boon possible to the 
cheese-maker if we could in some way enable him to correct 
his abnormal ripening processes and be able always positively 
to insure the proper sort of ripening. Now this is plainly a 
matter which is connected with the planting of the proper 
kind of bacteria in a cheese and planting them under proper 
conditions. Different kinds of cheeses are on our markets. 
We have the Edam cheese, we have the pineapple cheese, we 
