On the Reaction of Leaves to Traumatic 
Stimulation. 
BY 
F. FROST BLACKMAN, M.A., D.Sc., 
Lecturer on Botany in the University of Cambridge , 
AND 
GABRIELLE L. C. MATTHAEI, 
Bathurst Student , Newnham College. 
With Plate XXIX, and five Figures in the Text. 
I N the course of the experiments on respiration which we 
have been carrying on for some time, we have come 
across some interesting phenomena connected with the 
reaction of leaves to experimentally produced injuries. We 
have followed these out to a certain extent and propose to 
•give now an account of the results. „ 
The vitality of cut-off leaves, kept in the dark but supplied 
with water, is considerable and much beyond general ex- 
pectation. Leaves of Cherry-Laurel remain healthy for 
perhaps fifty days in such conditions, and leaves of Oleander 
have been kept thus for several months without ever having 
a chance of obtaining any fresh carbon-nutriment, ^e 
behaviour of the respiration under these conditions we shall 
treat of elsewhere : here it may be noted that Oleander leaves 
invariably put out vigorous crops of adventitious roots from 
the stump of the leaf-stalk under these conditions, and that 
[Annals of Botany, Vol. XV. No. LIX. September, 1901.] 
N n 2 
