166 REPORT OF DEPARTMENT Of BACTERIOLOGY OF THE 
cases excellent growths have developed, in others but weakly 
ones. Jn the former, as already stated, active enzymic devel- 
opment occurred, in the latter very little, i.e., the enzymic de- 
velopment was directly proportional to the vigor of growth. 
The beef broth cultures have given less active enzyms than these 
vegetable media, as has been explained. We have, however, 
continued to use beef broth largely in our comparative studies 
for the reason that the enzymic activity is sufficient for those 
purposes and more reliance can be placed upon the uniformity 
of the medium. The addition of 2 per ct. sucrose leads to 
more vigorous growth of the organism, especially in the earlier 
stages before too great acidity developed, and it is significant 
that more of the precipitate and with more enzymic activity 
was developed in the sugar broth (medium No. 4) than in the 
plain broth (medium No. 3). 
Thus companion cultures of these two media nine days old, 
of which the sugar broth showed an acid reaction (+4.2 
per ct.) and the plain broth was practically neutral (-+-0.7 
per ct.), were rendered 80 per ct. alcoholic. The sugar broth 
yielded 0.3 per ct. of dry precipitate, the plain broth 0.25 
per ct. A comparison of these cultures on carrot sections 
showed the former to be twice as active as was the latter, i. e., 
to soften a like section in one-half the time. A repetition with 
these two media, precipitating on the sixth day, gave similar 
differences but a little less marked. The Dunham peptone 
solution has proved a very poor medium whether with or with- 
out the addition of sugar. The alcoholic precipitate from such 
cultures seven days old (media Nos. 1 and 2 above) have shown 
scarcely appreciable enzym content. 
In conclusion, then, we may note that there seems a perfect 
correlation between the rate and vigor of the growth of the 
organism and the amount of enzym developed, i. e., the more 
vigorous the growth the more enzym; that the presence 
of cell wall substance had no appreciable effect on the ‘amount 
of enzym developed; and that in beef broth cultures the addi- 
