240 £ BOTANICAL GAZETTE [APRIL 
EXPERIMENT II 
At the same time as the preceding experiment, four plants were 
placed in darkness. The other conditions of temperature and 
moisture were the same. The bell jars were covered with black 
cloth to exclude the light. 
Pot 5. One shoot (from a cut potato), 133™™ high, with small leaves. 
Pot 6. Two shoots (from a cut potato), 80 and 100™™ high, with small leaves. 
Pot 7. Three shoots (from a whole potato), 84, 63, and 25™™ high, with small 
leaves. 
Pot 8. Two shoots (from a whole potato), 63 and 25™™ high, with small 
leaves. 
Results 
No. 5. In darkness eleven days and no intumescences formed. 
No. 6. In darkness eleven days and no intumescences. 
No. 7. In darkness eleven days; in six days two or three intumescences were 
found on one leaf. 
8. In darkness eleven days and no intumescences. 
These plants were all small and their stems grew very rapidly in 
the dark. In the three cases where intumescences were not pro- 
duced, it was thought that this might be due to the rapidity of growth. 
Accordingly a more developed plant was chosen and placed under 
the same conditions. 
g. Two shoots (from a whole potato), 105 and 120™™ high, with large, 
valde leaves. In two days a few intumescences had formed upon one 
of the s 
It will i be noted that on two of the plants placed in darkness 
a few intumescences were formed. It was suggested that this might 
possibly be due to the fact that the bell jars were not absolutely light 
tight. Accordingly another pot was placed under the same condi- 
tions and the bell jar covered with several thicknesses of cloth to 
prevent light from filtering through the folds. 
Pot ro. Two shoots (from a whole A sara 180 and 96™™ high, with large 
leaves. No intumescences were forme 
These plants, after having been taken from darkness, were left 
in the light and allowed to develop their leaves. They were then 
covered with bell jars in the light and after eight days all the shoots, 
excepting those of pot 10, had developed intumescences. 
