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VARIATION 185

pression of that inheritance in development would
mean the absence of variation, there are many reasons
why this completeness of hereditary resemblance is
rare. For the inheritance seems to consist of sets of
hereditary qualities not in duplicate merely but in
multiplicate; they are not all of equal strength or of
equal stability; there may be a struggle amongst
them; and they are subject to changes induced by the
changes in the complex nutritive supply which the
parental body—their bearer—affords.

A variation, which makes its possessor different
from the parents, is often interpretable as due to some
Incompleteness of inheritance or in the expression of the
inheritance. It seems as if the entail were sometimes
broken in regard to a particular characteristic. Oftener,
perhaps, as the third generation shows, the inheritance
has been complete enough potentially, but the young
creature has been prevented from realising its entire
legacy. Contrariwise, it may be that the novelty of
the newborn is seen in an intensifying of the inherit-
ance, for the contributions from the two parents may,
as it were, corroborate one another.

But in many cases a variation turns up which we
must call novel, some peculiar mental pattern, it may
be, which spells originality, some structural change
which suggests a new departure. We tentatively in-
terpret this as due to some fresh permutation or com-
bination of the complex substances which form the
material basis of inheritance, and are mingled from two
sources at the outset of every life sexually reproduced.
It is not merely in an intermingling of maternal and
paternal contributions that a life begins, but of legacies
through the parents from remoter ancestors. The



	VARIATION 185 pression of that inheritance in development would mean the absence of variation, there are many reasons why this completeness of hereditary resemblance is rare. For the inheritance seems to consist of sets of hereditary qualities not in duplicate merely but in multiplicate; they are not all of equal strength or of equal stability; there may be a struggle amongst them; and they are subject to changes induced by the changes in the complex nutritive supply which the parental body—their bearer—affords. A variation, which makes its possessor different from the parents, is often interpretable as due to some Incompleteness of inheritance or in the expression of the inheritance. It seems as if the entail were sometimes broken in regard to a particular characteristic. Oftener, perhaps, as the third generation shows, the inheritance has been complete enough potentially, but the young creature has been prevented from realising its entire legacy. Contrariwise, it may be that the novelty of the newborn is seen in an intensifying of the inherit- ance, for the contributions from the two parents may, as it were, corroborate one another. But in many cases a variation turns up which we must call novel, some peculiar mental pattern, it may be, which spells originality, some structural change which suggests a new departure. We tentatively in- terpret this as due to some fresh permutation or com- bination of the complex substances which form the material basis of inheritance, and are mingled from two sources at the outset of every life sexually reproduced. It is not merely in an intermingling of maternal and paternal contributions that a life begins, but of legacies through the parents from remoter ancestors. The