458 BOTANICAL GAZETTE 
from the other. 
[DECEMBER 
It is probable that the horizontal position of the old 
stem is directly related to this result; and if so it would be referred 
to the influence of gravity. 
Fic. 7.—Part of transverse 
through hy pocotyl at level of the ne 
section 
w shoot: 
¢, cortex; ca, callus; m, se aa a p, 
periderm; v, vascular strands. 
points, such as have been 
called ‘latent buds,” and 
which in this sense can 
have only a hypothetical 
existence; but is gener- 
ally present in all meri- 
stem and expresses itself 
under favorable condi- 
tions. The evidence 
against wounding as a 
necessary condition for 
such production of new 
shoots is suggestive, and 
that against the theories 
of “polarity” and “‘latent 
buds” seems to be clear. 
UNIVERSITY OF CHICAGO. 
Fic 
The suggested conclu- 
sions are that in the case 
of the stem of Zamia the 
power of regeneration and 
of developing adventitious 
shoots and roots is present 
in all meristematic tissue; 
that in cases of mutilation 
the meristematic tissue 
chiefly concerned is the 
phellogen of the callus, that 
over the region of the cen- 
tral cylinder being more 
often successful than that 
over the cortex. This 
power does not seem to be 
localized in any definite 
.8.—Piece of stem showing two shoots 
and a root springing from one end and a shoot 
from the other end. X # 
