154 Report oF DEPARTMENT OF BACTERIOLOGY OF THE 
oF 

Fic. 2. DIAGRAMS TO SHOW METHOD AND RESULTS OF TESTING THE DIF- 
FUSIBILITY OF THE ENZYM THROUGH AGAR. 
No. 1, surface view; 2, vertical section of the same along dotted line ee; 
a—a, sterile slice of living turnip root; b—b, layer of nutrient agar bearing 
the bacterial colony c-c; d-d, region of most active enzymic action; the 
extent of softened tissue at the end of 24 hours is indicated by the dotted 
area in No, 2; No. 3 shows a single cell of this softened turnip tissue. 
At the end of twenty-four hours, examination of this con- 
trol, D, showed the turnip underneath the agar to be un- 
changed, cxcept for a slight yellowish stain imparted by the 
agar to the surface; no softening whatever had developed. 
Upon lifting the agar in the first dish, A, the turnip showed 
an area immediately underlying the colony and somewhat 
larger than the surface spread of this in which the tissues 
were slightly browned and softened exactly as where invaded 
by the organism. Bits of this rotten turnip tissue were im- 
