s, thrown out from the same original stem.[10] The
same process of grafting occurs sometimes in the roots, as in _Taxus
baccata_ mentioned by Moquin, and also in the aerial roots of many of
the tropical climbing plants, such as _Clusia rosea_, &c.

[Illustration: FIG. 3.--Fasciation in Lettuce.]

=Fasciation.=--In the preceding instances of union between the branches,
&c., the actual number of the fused parts is not increased; but if it
happen that an unusual number of buds be formed in close apposition, so
that they are liable to be compressed during their growth, union is very
likely to take place, the more so from the softness of the young
tissues. In this way it is probable that what is termed fasciation is
brought about. This is one of the most common of all malformations, and
seems to affect certain plants more frequently than others. In its
simplest form it consists of a flat, ribbon-like expansion of the stem
or branch; cylindrical below, the branches gradually lose their pristine
form, and assume the flattened condition.

[Illustration: FIG. 4.--Fasciation in _Asparagus_.]

[Illustration: FIG. 5.--Fasciated branch of _Pinus Pinaster_.]

Very generally the surface is striated by the prominence of the woody
fibres which, running parallel for a time, converge or diverge at the
summit according to the shape of the branch. If the rate of growth be
equal, or nearly so, on both sides, the stem retains its straight
direction, but it more generally happens that the growth on one side is
more rapid and more vigorous than on the other, and hence arises that
curvature of the fasciated branch so commonly met with, _e.g._ in the
ash (_Fraxinus_), wherein it has been likened to a shepherd's crook. It
is probable that almost any plant may present this change. It occurs
alike in herbaceous and in woody plants, originating in the latter case
while the branches are still soft. It may be remarked that, in the case
of herbaceous plants, the fasciation always affects the principal stem,
while, on the other hand, in the case of trees and shrubs the deformity
occurs most frequently in the branches; thus, while in the former it
may be said that the whole of the stem is more or less affected, in the
latter it is rare to see more than one or two branches of the same tree
thus deformed. It is a common thing for the fasciated branch to divide
at the summit into a number of subdivisions. These latter may be
deformed like the parent bran