18 JOURNAL OF THE EOYx\.L HORTICULTURAL SOCIETY. 
would be no evolution ; and thirdly, we have the survival of the fittest, 
which must result from the struggle. The grand and universal struggle 
for existence compels the operation of Darwin's great principle, Natural' 
Selection. This term most completely expresses the process of evolution, 
a process which must result in the survival of the fittest, or, if preferred, 
the survival of the fittest to survive. 
It may be noticed that I do not take heredity as one of my principal 
factors. It need not, I think, be associated with any abstract theory of 
evolution. We might even go so far as to say that the inheritance of 
character is possibly itself an acquired character.' At the same time 
heredity must be so supremely important that it is impossible to speak 
of evolution without reference to it. Heredity is undoubtedly the same 
both in the garden and in nature, so that my argument cannot therefore 
be affected by it. Suffice it to say that everything — as pointed out by 
Carriere and others— tends to become hereditary. But I am compelled, 
because of its interest and because new light is just now rising above the 
horizon, to venture some remarks, which are perhaps new, upon the 
theory. By Mr. Walter Gardiner's researches we have now complete 
knowledge that a plant does not consist, as we used to think, of innume- 
rable particles of protoplasm, separated by cell-wall, but that, in fact, it 
consists practically of one single mass of protoplasm, of which cell-wall 
is merely the support. Now the point is this, that in consequence of this 
knowledge we gain a new or at least an enlarged theory of heredity. In either - 
case it must be an approximate of Darwin's theory known as pangenesis," 
which supposes the arrival of gemmules from all parts of the plant to be 
represented in the formation of the germ. Since protoplasm is connected 
by means of threads throughout the plant, there is no physical difficulty 
in the passage of Darwin's gemmules ; and I ask, is it not an instance of 
Darwin's wonderful sagacity that he should have propounded a theory 
of heredity which to-day is infinitely a better theory than he could ever 
have known it would be ? There is now no longer any need, I think, for 
that clever theory of Weismann's, known as Weismannism, which sup- 
poses the continuity of germ plasm as a plasm separate and distinct 
from the body plasm. Germ plasm and body plasm are, in fact, 
intimately connected, and one very im[)ortant result of this knowledge is 
that we are free to believe in the inheritance of acquired characters, a 
thing which Weismann's theory could not permit. Darwin was a strong 
believer in the inheritance of acquired characters, and I think it may be 
said now, from what we know of the constitution of the plant, that they 
are much more likely than not to be inherited. For the above view of 
the bearing of protoplasmic continuity upon the theory of heredity I have 
to accept the responsibility, but that we have our present advanced 
knowledge of the continuity of protoplasm itself is due entirely to the 
researches of Mr. Walter Gardiner, F.R.S., who has kindly given me a 
copy of his latest report to the Government Grant Committee of the 
Royal Society. The knowledge we get is so far-reaching, and must bear, 
I think, so strongly upon the theory of heredity, that I beg to quote as 
follows from the above-mentioned report, which is dated January 29, 
1900 :— 
" The result may be summarised as follows. Although we have only 
