THE ORCHID REVIEW. 
Wot. AVIA4 OCTOBER, 1908. [No. Igo. 
VARIATION AND INHERITANCE. 
THE British Association for the Advancement of Science has just held its 
meeting at Dublin, and it was appropriate that in the jubilee year of the 
publication of the theory of the Origin of Species by Natural Selection the 
President should have been a son of one of the original authors, Dr. Francis 
Darwin, M.A., F.R.S., who has himself contributed largely to our know- 
ledge of the movements of plants. In his inaugural address he pointed out 
that there had not been a botanical President since the Norwich meeting 
forty years ago, when Sir Joseph Hooker was in the chair, and spoke in 
eloquent and felicitous words in defence of the doctrine of Evolution. 
Excusing himself from a general survey of the progress of the theory during 
the last fifty years, he devoted himself to the subject of the movements 
of plants, and its bearing on the question of Evolution. 
He attempted to give a general idea of how changes of condition act as 
stimuli, and compel plants to execute certain movements, ard then went on 
to show that what was true of those temporary changes of shape, described 
as movements, is also true of those permanent alterations of shape known 
as morphological. He insisted that if the study of movement includes the 
problem of stimulus and reaction, morphological changes must be investi- 
gated from the same point of view. The two must be classed together, and 
this showed that the dim beginnings of habit or unconscious memory found 
in plants and animals, must find a place in morphology. A striking 
instance of correlated morphological change was to be found in the develop- 
ment of the adult from the ovum, and he took this ontogenic series and 
attempted to show that here also something equivalent to memory or habit 
Teigns. The fact that plants must be classed with animals in the manner of | 
their reaction to stimuli has now become almost a commonplace of 
Physiology. An organism is a machine that can be set free by some kind 
of releasing mechanism, but the result was out of all proportion to the 
Original stimulus. We could, asa rule, only know the stimulus and the 
Tesponse, the intermediate processes of the mechanism were hidden in the 
That big changes would result from small 
Secret life of protoplasm. 
s clear that the success of an 
Stimuli might have been guessed, since 1t wa 
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