5 22 
Chaudhuri .— A Study of the Growth in 
The following are the average measurements in mm. of the diameter of 
colonies in mm. at 25 0 C. from the fourth till the sixteenth day in Coon’s 
medium of full strength, half strength, and quarter strength : 
Days. 
N/i 
N/ 2 
N /4 
4 
7'5 
7.8 
8-3 
5 
9*5 
10.0 
10.3 
6 
12.5 
13.2 
13.2 
7 
15.0 
17.0 
17-0 
8 
18.2 
19-8 
19.8 
9 
21-8 
23.8 
23.8 
10 
25*5 
27-0 
27.0 
11 
29.2 
31.0 
31.0 
12 
33 -o 
34-5 
34*5 
13 
36. S 
38.0 
38-6 
14 
40.0 
41.8 
41.6 
15 
43-8 
45 *° 
44.6 
16 
47*5 
48* 2 
48-6 
mrn z 
2200 
1800 
g 1400 
1000 
c 
600 
200 
4 5 6 7 8 9 10 11 12 13 14 15 \ldays 
Fig. 2. Growth of V. albo-atrum on the different strengths of Coon’s medium with agar. 
The broken line represents growth on full strength (N/i), the continuous line that on half strength 
(N/2), and the dotted line that on quarter strength (N/4). The growth is measured by the area of 
the plate covered by the mycelium ; the area is estimated in terms of the square of the diameter 
measured in mm. 
Fig. 2 shows the result graphically. It depicts surface growth of the 
fungus as determined by taking the squares of the diameter of the circular 
area covered by the fungus growing at 25 0 C. The rate of growth in area 
is seen to increase with the increasing diameter of the mycelium, thus 
following approximately the compound interest law. 
