298 ; BOTANICAL GAZETTE [OCTOBER 
its bud. In fig. ro one shoot had been formed in the lower leaf, 
which had commenced to grow later than the two shoots in the 
completely isolated leaf in fig.8. This drawing was made 5 weeks 
after the beginning of the experiment. These 3 specimens repre- 
sent 3 different de- 
grees of “ 
away from the 
notches of the leaf. 
In the leaf shown in 
fig. 9 the suction from 
the stem was too 
strong and no notches 
of the leaf grew. In fig. ro the suction was 
less and one notch showed growth, which 
was less rapid than in fig. 8. In fig. 8, 
the completely isolated leaf, there was no 
Fic. 12 P16, ti Fic. 10 
“suction” away from the leaf and the growth of the notches was 
most rapid. 
A digression is necessary to explain why in fig. 10 only the lower 
leaf has formed a shoot and not the upper leaf also. The writer 
is inclined to ascribe the phenomenon chiefly, if not exclusively, to 
the influence of moisture. The specimens were suspended in a 
glass trough loosely covered with a glass plate and whose bottom 
contained a layer of water. The air surrounding the lower leaf was 
more completely saturated with water vapor than that surrounding 
