d
others single, by neglect or care: these characters can be transmitted
by cuttings or grafts, and in some cases by true or seminal propagation.
Occasionally a single bud on a plant assumes at once a new and widely
different character: thus it is certain that nectarines have been
produced on peach trees and moss roses on provence roses; white
currants on red currant bushes; flowers of a different colour from that
of the stock, in Chrysanthemums, Dahlias, sweet-williams, Azaleas, &c.,
&c.; variegated leaf-buds on many trees, and other similar cases. These
new characters appearing in single buds, can, like those lesser changes
affecting the whole plant, be multiplied not only by cuttings and such
means, but often likewise by true seminal generation.

{188} <It is not clear where the following note is meant to come>:
Case of Orchis,--most remarkable as not long cultivated by
seminal propagation. Case of varieties which soon acquire, like
_AEgilops_ and Carrot (and Maize) _a certain general character_ and
then go on varying.

The changes thus appearing during the lives of individual animals and
plants are extremely rare compared with those which are congenital or
which appear soon after birth. Slight differences thus arising are
infinitely numerous: the proportions and form of every part of the
frame, inside and outside, appear to vary in very slight degrees:
anatomists dispute what is the "beau ideal" of the bones, the liver and
kidneys, like painters do of the proportions of the face: the proverbial
expression that no two animals or plants are born absolutely alike, is
much truer when applied to those under domestication, than to those in a
state of nature{189}. Besides these slight differences, single
individuals are occasionally born considerably unlike in certain parts
or in their whole structure to their parents: these are called by
horticulturists and breeders "sports"; and are not uncommon except when
very strongly marked. Such sports are known in some cases to have been
parents of some of our domestic races; and such probably have been the
parents of many other races, especially of those which in some senses
may be called hereditary monsters; for instance where there is an
additional limb, or where all the limbs are stunted (as in the Ancon
sheep), or where a part is wanting, as in rumpless fowls and tailless
dogs or cats{190}. The effects of external conditions on the size,
colour and f