248 Scientific Intelligence. 
influence must be transmitted, bends and carries the point away 
impinges upon the stone or other body, it will bend at that part 
toward instead of away from it, and so follow along its surface. 
gravitation. Well may Mr. Darwin affirm that there is no strue- 
ture in plants more wonderful, as far as its functions are concerned, 
of plants and many of the actions performed unconsciously by 
the lower animals.” “But the most striking resemblance 1s the 
localization of their sensitiveness and the transmission of an Ie 
uence to an excited part which consequently moves. Yet plants 
do not of course possess nerves or a central nervous system; an 
t it 
more perfect transmission of impressions and for the more com- 
plete intercommunication of the several parts.” The closing sem 
tence of the book may be appended to this. “It is hardly an 
Pat to say that the tip of the radicle, th 
th has ceased whenever pulvini are p » as in several 
classes of leaves. s respects the relation of external agents te 
the movements, note Mr. Darwin’s rem en we speak 0 
of light and darkness, gravitation, slight pressure or other ITF 
tants and certain innate or constitutional states of the plant, do 
not directly cause the movement; they merely lead to a tem 
rary increase or diminution of those spontaneous changes 1? the 
turgescence of the cells which are already in progress. : i 
_ Certai s of plants turn or grow earthward. When this 
is attributed to gravitation, as it commonly is, the physicis® 
have opportunity to complain of a misuse of the term. Althoug 
Mr. Darwin, like other writers, speaks of the influence of light 
and of gravitation in the same breath, without consiergag se 
i ; who 
he earth as the 
direct result of gravitation,” and note especially the concluding 
dictum. ‘Gravity does not appear to act in a more direct man- 
. ” 
which moves away when it feels some weight or = 
