1916] LOEB—BRYOPHYLLUM 207 
inhibited but only delayed; while if such a leaf is suspended in air 
the growth of the notches is generally permanently suppressed. 
Hence if it were possible to repeat the experiment with leaves 
nage entirely in air the results should be still more striking. 
It was found that if ‘the two leaves con- 
nected by their node are large (and probably 
rich in sap ?) they will give rise to new roots 
and shoots in their notches even if sus- 
pended in air. In figs. 6 and 7 two such 
pairs of leaves of different sizes from the 
same plant were suspended in moist 
air. The larger leaves (fig. 6) have each 
formed 5 shoots in their notches, although 
also one of the axil- 
lary buds of the stem 
had grown out. This oe 
latter growth was / 
not able to inhibit 
the growth of the 
notches. In the 
smaller leaves (fig. 7) 
no growth had taken 
place in the notches. 
The drawing was made 19 days after the 
commencement of the experiment. The 
moderate “suction” of the stem sufficed to 
Suppress the growth of the notches in the 
smaller but not in the larger leaves when 
suspended in moist air. 
Figs. 8, 9, and 10 are the replica of the 
experiment represented in figs. 3, 4, and 5, 
but with the difference that in figs. 8, 9, 
and ro the leaves were entirely in air. The FIG. 9 
leaves were large and gave a characteristic result. The completely 
isolated leaf (fig. 8) had formed two large shoots from notches; the 
leaf of fig. 9 had formed neither roots nor shoots in its notches on 
account of the complete inhibitory effect of the piece of stem and 
Fic. 8 
