y under the
most unnatural conditions (for instance, the rabbit and ferret kept
in hutches), showing that their reproductive system has not been thus
affected; so will some animals and plants withstand domestication or
cultivation, and vary very slightly--perhaps hardly more than in a state
of nature.

A long list could easily be given of "sporting plants;" by this term
gardeners mean a single bud or offset, which suddenly assumes a new and
sometimes very different character from that of the rest of the plant.
Such buds can be propagated by grafting, etc., and sometimes by seed.
These "sports" are extremely rare under nature, but far from rare under
cultivation; and in this case we see that the treatment of the parent
has affected a bud or offset, and not the ovules or pollen. But it is
the opinion of most physiologists that there is no essential difference
between a bud and an ovule in their earliest stages of formation; so
that, in fact, "sports" support my view, that variability may be largely
attributed to the ovules or pollen, or to both, having been affected by
the treatment of the parent prior to the act of conception. These cases
anyhow show that variation is not necessarily connected, as some authors
have supposed, with the act of generation.

Seedlings from the same fruit, and the young of the same litter,
sometimes differ considerably from each other, though both the young
and the parents, as Muller has remarked, have apparently been exposed to
exactly the same conditions of life; and this shows how unimportant the
direct effects of the conditions of life are in comparison with the laws
of reproduction, and of growth, and of inheritance; for had the action
of the conditions been direct, if any of the young had varied, all would
probably have varied in the same manner. To judge how much, in the case
of any variation, we should attribute to the direct action of heat,
moisture, light, food, etc., is most difficult: my impression is, that
with animals such agencies have produced very little direct effect,
though apparently more in the case of plants. Under this point of view,
Mr. Buckman's recent experiments on plants seem extremely valuable.
When all or nearly all the individuals exposed to certain conditions are
affected in the same way, the change at first appears to be directly
due to such conditions; but in some cases it can be shown that quite
opposite conditions produce similar changes of structure. Never