432 
LEWIS KNUDSON 
licate, but contamination or failure to germinate caused a loss of 
some of the cultures. The seed were sterilized by immersion in a 
solution of calcium hypochlorite (calcium oxychloride, Baker) ac- 
cording to the method of Wilson (1915). The peas were treated for 
two hours and the wheat for five hours. The results are given in 
Table i. 
Table i 
Influence of Sugars on the Toxicity of Galactose 
The Concentration of Each Sugar Equals 0.025 Mol. 
Length of 
Primary 
Root (Cm.) 
Average 
Length 
of Lateral 
Root (Cm.) 
Length of 
Top (Cm.) 
Class 
of Injury 
Galactose (3 cultures) 
I 
6 
5 
Galactose (2 cultures) 
0 
0 
3 
6 
Glucose (3 cultures) 
10 
8 
15 
0 
Levulose (3 cultures) 
8 
8 
14 
0 
Arabinose (i culture) 
10 
7 
15 
0 
Saccharose (3 cultures) 
9 
8 
14 
0 
Maltose (3 cultures) 
10 
8 
13 
0 
Raffinose (2 cultures) 
9 
8 
14 
0 
Pfeffers, no sugar (3 cultures) 
10 
8 
14 
0 
Galactose +glucose (3 cultures) 
9 
7 
0 
Galactose +levulose (2 cultures) 
io>^ 
4 
Galactose + levulose (i plant) 
7 
0 
5 
Galactose -f-saccharose (3 cultures) 
3 
7 
13 
I 
Galactose -|-saccharose (i culture) 
10 
9 
14 
0 
Galactose 4- lactose (3 cultures) 
I 
y2 
9 
5 
Galactose + maltose (2 cultures) 
I 
10 
5 
Galactose +raffinose 
I 
y 
6 
5 
From the table it will be noted that the toxicity of galactose is 
prevented by glucose or saccharose, the former being slightly more 
effective than the latter since the primary root is not killed in the 
presence of glucose. None of the other sugars are effective in pre- 
venting the injurious action of galactose, although in the presence of 
levulose the primary root may continue its growth to a limited extent. 
Representative cultures are shown in Fig. i. 
All of the preceding experiments except those with levulose were 
repeated and similar results were obtained. 
In some earlier experiments (Knudson, 1916) it was noted that 
. glucose does not antidote galactose if the concentration of the former 
is less than that of the latter. It was thought that some relation might 
be found between concentrations and antagonistic action. Accord- 
ingly the galactose was supplied in each case at a concentration of 
0.0125 mol. solution, and the other sugars used at double this concen- 
