38 Report OF THE BACTERIOLOGIST OF THE 
present, were not sufficiently numerous to cause trouble until 
August 15. On this date blotches were formed, though fortu- 
nately they were obscured by the cheese-color. It so chanced 
that the steaming of the utensils occurred on this day and not a 
single red point could be found in the sample from the cheese of 
August 16. The small red points in the colored cheese were so 
difficult to detect with the unaided eye that the maker overlooked 
them and thought that the trouble had disappeared. Accordingly 
he restricted the heating to the utensils placed in the curd sink 
on August 19, 21 and 31, and then entirely ceased the steaming. 
Left to itself the trouble increased again until the cheese-color 
failed to cover up the blotches on August 28, September 1, 3, 6, 
7, 9, 10 and 11. The factory was visited on September 10 and — 
the actual condition brought to the attention of the maker. After 
this date the vat and utensils were steamed regularly three times 
per week. The number of spots decreased rapidly, and during 
the first half of October entirely disappeared for over two weeks. 
The principal results of this season’s experience at this factory 
may be summarized as follows: 
(1) In making moist, home-trade cheese, coloring alone can 
not be relied upon to cover up rusty spot. 
(2) The marked difference in the development of the spots in 
cheese made upon the same day in different vats can best be 
explained by assuming an introduction of germs with the milk. 
(3) In all but exceptional circumstances careful steaming, 
three times per week, will keep the trouble below the point where 
it will cause financial loss. 
While the spots were kept below the point where they would 
cause financial loss upon the cheese, their almost constant pres- 
ence indicated that there was a seed bed which our present 
methods did not reach. The work of 1902 was mainly directed 
toward determining the source of supply. 
WORK AND RESULTS AT FACTORY NUMBER TWO IN 1902. 
Although we kept in touch with the factory from the opening 
of the season, it was not until July 24 that we received samples 
showing the red points. , 
On July 31 we collected quart samples from the milk of each 
of the 31 patrons, and from each sample we made a little cheese, 
