New YorK AGRICULTURAL EXPERIMENT STATION. 49 
fected cheese with the aim of finding the habits of the causal 
organism. In all, a dozen infected cheeses have been made be- 
side the appropriate controls. 
Of these, three were made at different times each with the ad- 
dition of a half dozen plugs drawn from a cheese thoroughly 
spotted with the trouble. These plugs were first rubbed to a 
thin paste with water and then added to the vat before it was 
set with the rennet. In each of these experimental cheeses the 
spots which developed were so widely scattered that they would 
have passed any but a very careful inspector, and these three 
trials may be put down as failures as far as the production of 
spots in the cheese is concerned. 
Seven cheeses were made with the addition of a culture of the 
causal organism to the milk before adding the rennet, and these 
likewise failed to produce more than a few red points scattered 
through the mass of the cheese, and as far as practical considera- 
tions are concerned these can also be classed as a failure to pro- 
duce anything approximating what is commercially known as 
rusty spot. 
Two cheeses manufactured at different times and using cul- 
tures derived from outbreaks in different factories were made by 
adding a culture to the vat just after the curd had been cut. In 
each case the interior of the uncolored cheese within ten days 
was so abundantly filled with small red points that at first glance 
these colored points seemed to blend and give the entire cheese a 
high red color. 
While these observations are too few to be relied upon as prov- 
ing anything regarding actual conditions in the factory they are 
in many ways very suggestive. In the first place these experi- 
ments show that a cheese may contain a large number of the 
proper kind of germ and still not show any discoloration. This 
may throw some light upon the failure of the spots to appear in 
the make of certain days in an infected factory. 
Again, these results suggest that the stage of the process when 
the germs enter the vat may be very important. When the milk 
is curdled by the rennet all these minute plants within the mass 
4 
