Igo ; BOTANICAL GAZETTE [ SEPTEMBER 
strated that the stimulus, in response to which curvature takes 
place, is transmitted in the cortex, either of the convex or con- 
cave side, and that the root in curving takes advantage of 
tensions already existing. In an unstimulated root the tissue 
tensions are such that every side tends to curve the root away 
from that side. These tendencies balance each other and the 
root grows straight. When the root is stimulated (as by wound- 
ing one side of the tip) an impulse is transmitted along the 
cortex as far as the curvature extends. The impulse produces 
on the side farthest from the wound a change in the protoplasm 
of the cortical parenchyma which makes it more permeable to 
water. The elasticity of the cell walls forces water out of the 
cells into the intercellular spaces. This shortens the cells of 
that side. At the same time the stimulus causes an extension, 
probably a growth, of the cells on the side that becomes convex. 
Both sides of the roots are active in producing the curvature, 
but their activities are of a different kind. The axial cylinder 
remains neutral and curvature necessarily follows. 
FREDERICK C. NEwcomBeE: Cellulose ferment.— Account of 
the action of a cellulose dissolving enzyme extracted from 
cotyledons of seedlings of Lupinus albus. 
Ropney H. True and C. G. Hunxei: Zhe tox action of 
phenols on plants—A study of the toxic action of phenols on living 
plants shows that they act less sharply and less severely than 
acids and heavy metals. Electrolytic dissociation plays a much 
less active role, generally speaking, than is the case in those 
classes of compounds, the toxic effect being due in the main to 
the undissociated molecules. Various radicals, when introduced 
into the molecule, exert a specific effect. The number of OH 
groups present, from one to three, does not directly affect the 
toxic action of phenols. The introduction of an OCH, group 
does not increase the toxic action of phenols. The introduction 
of one or more NO, groups, the substitution of a CH, group for 
an OH group, the presence of a C,H, group or a COOH group, 
all increase in some measure the toxic action of the substance 
It seems certain that when plants are raised under constant con- 
