THE HAMILTON ASSOCIATION 87 
THE PROBABLE COURSE OF EVOLUTION IN PLANTS. 
J. B. Turner, B.A., Vice-Principal Hamilton Coll. Institute. 
[Illustrated by numerous lantern slides. ] 
The hypothesis of evolution in the organic world has had for 
its chief support the phenomena of animal structure and life. 
These phenomena have been studied so carefully and compre- 
hensively that there are but few who have given the subject any 
attention that have not accepted the hypothesis in one form or 
another as affording a fairly reasonable explanation of the origin 
of the different forms found in the animal world. There may be 
wide divergences of opinion as to the details, but on the great 
general principle there is a wonderful unanimity. 
For plants, however, there has not been the same working 
out of details. The general acceptance of the hypothesis in so far 
as plants are concerned seems to have come about to some extent 
by analogy. As a consequence the course along which the com- 
plex higher plants have been evolved from the lower forms is not 
clearly defined, nor has any one course been generally accepted 
as the most probable one. It is my present purpose to offer a few 
suggestions on this very important matter, not so much with the 
view of giving a complete statement of what I believe to be the 
course of the evolution of plant forms as to indicate some of the 
most conspicuous landmarks in the long pathway from the lower 
to the higher forms. 
In dealing with this progress from one form to another it 
is necessary that it be made clear at the outset what structures or 
organs are of importance in marking out the way, so that there 
may be no misunderstanding of the relative values of the different 
structures and organs in such a discussion. 
Students of plant forms who, in recent years, have in any 
