449 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1914. 
short as the single beat of the pendulum. The various magnifica- 
tions available are a thousand or ten thousand times. For demon- 
stration purposes I have been able to secure a magnification of a 
million times. The infinitesimal growth thus becomes magnified so 
as to appear rushing forward as if in a race. The actual rate of 
growth and its variations under the action of drugs, of food materials, 
of various electrical and other forms of stimuli, are thus recorded in 
the course of a few minutes. The great importance of this method 
of investigation in agriculture is sufficiently obvious. 
The plant has thus been made to exhibit many of the activities 
which we have been accustomed to associate only with animal hie. 
In the one case, as in the other, stimulus of any kind will induce a 
responsive thrill. There are rhythmic tissues in the plant which, 
like those in the animal, go on throbbing ceaselessly. These spon- 
taneous pulsations in the one case, as in the other, are affected by 
various drugs in an identical manner. And im the one case, as in 
the other, the tremor of excitation is transmitted with a definite and 
measured speed from point to point along conducting channels. The 
establishment of this similarity of responsive actions in the plant 
and animal will be found of the highest significance; for we now 
realize that it is by the study of the simpler phenomena of irritability 
in the vegetal organisms that we may expect to elucidate the more 
complex physiological reactions of the animal. 
THE PLANT’S RESPONSE TO THE SHOCK OF DEATH. 
A time comes when, after an answer to a supreme shock, there is 
a sudden end of the plant’s power to give any further response. 
This supreme shock is the shock of death. Even in this crisis there 
is no immediate change in the placid appearance of the plant. 
Drooping and withering are events that occur long after death itself. 
How does the plant, then, give this last answer? In man, at the 
critical moment, a spasm passes through the whole body, and similarly 
in the plant I find that a great contractile spasm takes place. This 
is accompanied by an electrical spasm also. In the script of the 
death recorder the line, that up to this pomt was being drawn, 
becomes suddenly reversed and then ends. This is the last answer 
of the plant. 
These, our mute companions, silently growing beside our door, 
have now told us the tale of their life tremulousness and their death 
spasm in script that is as inarticulate as they. May it not be said 
that this, their story, has a pathos of its own beyond any that we 
have conceived ? 
We have now before our mind’s eye the whole organism of the 
perceiving, throbbing, and responding plant, a complex unity and not 
a congeries of unrelated parts. The barriers which separated kindred 
