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be torn apart by the needle. When the surface is scraped with a needle, 
the white covering is removed, revealing a brown substratum. This form 
grows rapidly in agar, wort gelatine, blood serum, starch and flour pastes. 
The form liquefies wort gelatine slowly, and hard, white lumps float on 
the surface. This bacterium is a facultative anaerobic bacillus, very 
short and possessing no movement. Its size is 1x1% u. Old cultures give 
a distinct odor of old hay. The cultures of starch and flour pastes con- 
taining this form were tested with Fehling’s solution to determine the 
diastasic action, with the result that both the starch and flour pastes 
showed a very marked action of the changing of starch to sugar, the ac- 
tion in the flour paste being more marked. Highty-five per cent. of the 17 
species grew well in blood serum, the form described above being the 
most luxuriant grower. It is a curious fact that bacillus subtilis, a form 
appearing in large numbers on grain, does not appear in the flour. There 
is not sufficient heat produced in the roller process to kill the bacillus, 
hence its elimination cannot be traced to that. It has been suggested that 
possibly the form lived on the husk or bran and clung to it and was thus 
eliminated. This is only a supposition, however. About 40 per cent. of the 
different species produced a marked diastasie action in flour and starch 
pastes, 
Briant, Walsh, and Waldo, English chemists, made investigations on 
this subject, and the conclusions arrived at by them are as follows: The 
lower the grade of flour, the greater the number of organisms present. 
That under similar conditions, sourness is far more likely to occur in bread 
made from low-grade flours. 
The writer's investigations of flours confirm the above results. 
DESCRIPTION OF FORMS. 
Flour No. 1 contains 3 forms: a (1), B (1) (c). 
a(l) Is a facultative anaerobic, non-liquefying micrococcus. Grows well in 
agar but not so well in wort gelatine. Has a grayish color grown on agar. Col- 
onies oily, and smooth, Size is 1}. Arranged in twos and fours, and possesses 
no movement. Does not grow on blood serum. 
BQ) Is a facultative anaerobic, non-liquefying bacillus. Grows well in agar, 
but poorly in wort gelatine. The colonies are grayish white in color, dull, dry 
and floury, with convoluted edges. Possesses a slow, waddling movement. Size, 
3—9M 1p. 
