to describe the Mendelian theory,[6] which is well known, at least
to all biological readers, though one or two points in connection with
it may yet have to be touched upon.

The point of cardinal importance in connection with Mendelism is that it
does reveal a law capable of being numerically stated, and apparently
applicable to a large number of isolated factors in living things.
Indeed it was this attention to isolated factors which was the first and
essential part of Mendel's method. For example, others had been content
to look at the pea as a whole. Mendel applied his analytic method to
such things as the colour of the pea, the smooth or wrinkled character
of the skin which covered it, its dwarfness or height, and so on.

Now, the behaviour of these isolated factors seems to throw a light even
upon the vehicle of heredity. We often talk of "blood" and "mixing of
blood," as if blood had anything to do with the question, when really
the Biblical expression "the seed of Abraham" is much more to the point.
For it is in the seed that these factors must be, whether they be mnemic
or physical. Professor Bateson (M., p. 5) thinks it obvious that they
are transmitted by the spermatozoon and the ovum; but it seems to him
"unlikely that they are in any simple or literal sense material
particles." And he goes on to say, and this, I think, is one of his most
important statements: "I suspect rather that their properties depend on
some phenomenon of arrangement."

Now, if there be a law behind the phenomena made clear to us by
Mendelian experiments (as Mendelians are never tired of asserting), then
it becomes in no way impertinent to ask how that law came into
existence, and who formulated it. Darwinism, according to Driesch,[7]
"explained how by throwing stones one could build houses of a typical
style." In other words, it "claimed to show how something purposively
constructed could arise by absolute chance; at any rate this holds of
Darwinism as codified in the seventies and eighties." Of course the
Blind Chance doctrine breaks down utterly when it comes to be applied to
selected cases, and nothing more definitely disposes of it than the very
definite law which emerges as the result of the Mendelian experiments.
That is obvious to the prophets of Mendelism; but, whilst they admit
this, they will have nothing to say to the lawgiver. That is the
"rankest metaphysics," as Dr. Johnstone puts it,[8] or "mysticism," as
others prefe