18 PRESIDENT’S ADDRESS. 
tion of a few, as they still are, many and long discussions must 
inevitably arise on the question, and I offer these remarks to pre- 
pare the ground. I ask you simply to open your minds to this 
possibility. It involves a certain effort. | We have to reverse our 
habitual modes of thought. At first it may seem rank absurdity to 
suppose that the primordial form or forms of protoplasm could have 
contained complexity enough to produce the divers types of life. But 
is it easier to imagine that these powers could have been conveyed by 
extrinsic additions ? Of what nature could these additions be? Additions 
of material cannot surely be in question. We are told that salts of 
iron in the soil may turn a pink hydrangea blue. The iron cannot be 
passed on to the next generation. How can the iron multiply itself? 
The power to assimilate the iron is all that can be transmitted. A 
disease-producing organism like the pebrine of silkworms can in a very 
few cases be passed on through the germ-cells. Such an organism can 
multiply and can produce its characteristic effects in the next genera- 
tion. But it does not become part of the invaded host, and we cannot 
conceive it taking part in the geometrically ordered processes of segre- 
gation. These illustrations may seem too gross; but what refinement 
will meet the requirements of the problem, that the thing introduced 
must be, as the living organism itself is, capable of multiplication and 
of subordinating itself in a definite system of segregation? That which 
is conferred in variation must rather itself be a change, not of material, 
but of arrangement, or of motion. The invocation of additions extrinsic 
to the organism does not seriously help us to imagine how the power to 
change can be conferred, and if it prove that hope in that direction 
must be abandoned, I think we lose very little. By the re-arrangement 
of a very moderate number of things we soon reach a number of possi- 
bilities practically infinite. 
That primordial life may have been of small dimensions need not 
disturb us. Quantity is of no account in these considerations. 
Shakespeare once existed as a speck of protoplasm not so big as a 
small pin’s head. To this nothing was added that would not equally 
well have served to build up a baboon or a rat. Let us consider how far 
we can get by the process of removal of what we call ‘epistatic ’ factors, 
in other words those that control, mask, or suppress underlying powers 
and faculties. I have spoken of the vast range of colours exhibited by 
modern Sweet Peas. There is no question that these have been derived 
from the one wild bi-colour form by a process of successife removals. 
When the vast range of form, size, and flavour to be found among the 
cultivated apples is considered it seems difficult to suppose that all this 
variety is hidden in the wild crab-apple. I cannot positively assert that 
this is so, but I think all familiar with Mendelian analysis would agree 
with me that it is probable, and that the wild crab contains presumably 
