ransposed, while the upper portions or crowns were unaffected: the root
of one, naturally weak, became distended and enlarged by the abundant
matter poured into it by its new crown; and in like manner the root of
the other, naturally vigorous, was starved by insufficient food derived
from the new crown, and became diminutive and shrunken (see Synophty).

[Illustration: FIG. 22.--Adhesion of the branches of two elms. 'Gard.
Chron.,' 1849, p. 421.]

The explanation of the fact that the stumps of felled fir trees
occasionally continue to grow, and to deposit fresh zones of wood over
the stump, depends on similar facts. In _Abies pectinata_, says
Goeppert,[57] the roots of different individuals frequently unite; hence
if one be cut down, its stump may continue to live, being supplied with
nourishment from the adjacent trees to which it is adherent by means of
its roots.

[Illustration: FIG. 23.--Adhesion of two roots of carrot. 'Gard.
Chron.,' 1851, p. 67.]

A not uncommon malformation in mushrooms arises from the confluence of
their stalks (fig. 24), and when the union takes place by means of the
pilei, it sometimes happens, during growth, that the one fungus is
detached from its attachment to the ground, and is borne up with the
other, sometimes, even, being found in an inverted position on the top
of its fellow.[58]

The garden operations of budding, grafting and inarching have already
been alluded to as furnishing illustrations of adhesion, but it may be
well to refer briefly to certain other interesting examples of adhesion
induced artificially; thus, the employment of the root as a stock,
"root-grafting," is now largely practised with some plants, as affording
a quicker means of propagation than by cuttings; and a still more
curious illustration may be cited in the fact that it has also been
found possible to graft a scion on the leaf in the orange.[59]

[Illustration: FIG. 24.--Section through two adherent mushrooms, the
upper one inverted.]

Mr. Darwin, in his work on the 'Variation of Animals and Plants,' vol.
i, p. 395, alludes to the two following remarkable cases of
fusion:--"The author of 'Des Jacinthes' (Amsterdam, 1768, p. 124) says
that bulbs of blue and red hyacinths may be cut in two, and that they
will grow together, and throw up a united stem (and this Mr. Darwin has
himself seen), with flowers of the two colours on the opposite sides.
But the remarkable point is, that flowers are sometimes produ