520 
Chaudhuri.—A Study of the Growth in 
Coon’s medium (1) consists of MgS 0 4 , KH 2 P 0 4 , asparagin, and 
maltose. Coon advises the steaming of the solution on three successive 
days, but no difference in the nutritive value of the medium was to be 
observed between steaming and sterilizing at 120° C. 
V. albo-atrum grew very well in Coon’s normal solution. No signifi¬ 
cant difference in the dry weight of the growth occurred when, in a series of 
experiments, the asparagin was reduced by half; but whenever the maltose 
is reduced, the reduction in growth is very great. When maltose is present 
in full strength the reduction of asparagin does not make much difference ; 
again, if maltose is decreased to half neither can the addition of asparagin in 
full strength enhance the growth nor the reduction of asparagin diminish it. 
The following gives the actual dry weight of the growth of Verticillium 
in Coon’s medium with varying amounts of maltose and asparagin. These 
figures have been arrived at by estimating the dry weight of the fungus after 
sixteen days’ growth on various modifications of Coon’s medium with agar. 
The fungus was incubated at room temperature (i8 °-2 o° C.). The method 
of determining the dry weight is given later. 
Nor vial Coon. 
0.0460 grm. 
0-0363 „ 
°‘° 3 2 4 n 
0.0262 ,, 
0.0252 „ 
0-0242 ,, 
Av. 0.0317 + 0-002 grm. 
Coon s with half 
maltose and 
half asparagin. 
0-0302 grm. 
0.0231 „ 
0.0205 ,, 
0.0183 „ 
0-0167 ,, 
0-0155 „ 
Av. 0.0207+0-0013 grm. 
Coon s with half 
maltose and 
no asparagin . 
0.0297 grm. 
0.0277 » 
0-0220 ,, 
O.OI49 „ 
O.OI48 ,, 
O.OI32 „ 
Av. 0.0204 + 0-0018 grm. 
Coon s with full maltose 
and half asparagin. 
0.0380 grm. 
0-0313 „ 
0-0267 ,, 
0-0182 ,, 
0.0173 „ 
0-0164 55 
Av. 0.0246+ 0.0019 grm. 
Coon's with full 
maltose and 
no asparagin. 
0-0271 grm. 
0.0239 „ 
0.0234 ,, 
0.0230 „ 
0-0225 ,, 
0.0203 „ 
Av. 0-0234 + 0.0006 grm. 
Coon's with no 
maltose and 
half asparagin. 
o-o 124 grm. 
0-0084 >? 
0.0074 „ 
0-0067 ,, 
0-0066 ,, 
0-0061 ,, 
Av. 0-0079 + 0-0008 grm. 
Coon s with half maltose 
and full asparagin. 
0-0303 grm. 
0-0241 „ 
0-0221 „ 
0.0185 ,, 
0-0170 „ 
0*0158 ,, 
Av. 0.0213 + 0-0012 grm. 
Coon s with no maltose 
and full asparagin. 
o-o 166 grm. 
0-0102 ,, 
0-0084 ,, 
0-0076 ,, 
0.0074 „ 
0.0066 ,, 
Av. 0-0094 + 0.0008 grm. 
Coon's with neither 
maltose nor as¬ 
paragin. 
0-0074 grm. 
0.0040 „ 
0-0040 ,, 
0.0038 ,, 
0-0036 „ 
0-0036 „ 
Av. 0-0044 + 0-0004 grm. 
in Fig. 1, and here the 
The above data are represented graphically 
importance of maltose is very manifest. 
