g6 Frederic Czapek. — The Anti-ferment Reaction in 
VIII. 
I had already shortly mentioned in a previous paper ( 25 ) that the 
anti-ferment reaction occurs in roots laterally illuminated, which nevertheless 
show no trace of heliotropic curvature, even on the klinostat. As a source 
of light incandescent gas was used. It was found that roots of Ltipinus 
albus do not respond to illumination by curvatures under any conditions. 
But they nevertheless show a distinct anti-ferment reaction when laterally 
illuminated. 
In a large glass trough were placed 200 roots of Lupinus ; 100 of them 
were in direct contact with the glass wall, so that they could be illuminated 
laterally ; 100 other roots were completely surrounded by earth and kept in 
darkness. At a distance of one meter was placed the gas lamp, and the 
trough was laterally illuminated during two hours. The temperature near 
the roots in the earth was at first 20° C., at the end of the experiment %T C. 
The roots were then taken out and prepared. The reducing power 
was decreased in the following manner : — 
Illuminated 2-0 i*8 1-5 1-2 0-9 cc. ^ AgN 0 3 
Darkened . 2-0 1-5 11 o-8 0-4 „ „ 
The same results were obtained with Sinapis alba (cultivated in water), 
Phaseolus , Faba , Zea. Of these only the roots of Sinapis showed distinct 
heliotropic curvature. In all other species of roots I could not obtain 
distinct curvatures even by means of the klinostat. 
The anti-ferment reaction was, however, very distinct and certain in all 
cases, and this behaviour proves that the investigated roots were all 
sensitive to lateral illumination, even if they were mostly not able to show 
curvature. 
The effect of coloured light was investigated by means of ruby glass 
and of gelatine paper of several colours. Behind the ruby glass seedlings 
of Avena , which are very sensitive to the heliotropic stimulus, showed no 
curvature. Behind red, yellow, or blue gelatine paper, heliotropic reaction 
was observed. The anti-ferment test (with Lupinus roots) gave results 
strictly analogous to the direct observation of curvature in Avena : — 
Red gelatine paper . 
2-0 
1.8 
— 
11 
cc. — AgNO. 
IO & 3 
Control 
2-0 
i*6 
— 
o-6 
5 ) 
95 
Yellow gelatine paper 
2-0 
— 
1-2 
0.9 
55 
95 
Control 
2-0 
— 
o-8 
0.4 
99 
55 
Ruby glass .... 
2-0 
— 
0.9 
0.4 
55 
59 
Control 
2-0 
— 
o-8 
0.4 
55 
59 
Blue gelatine paper . 
2-0 
— 
1.4 
— 
95 
55 
Control 
2-0 
— 
o-6 
— 
55 
55 
