sts "folia bullata." In such leaves the disc of the leaf, rather
than the margin, is increased and its surface is thrown up into little
conical projections, which are hollow on the under side.

But leaves may increase beyond their usual size without such grave
alterations of form as those to which allusion has just been made. It is
well known that if a tree be cut down and new shoots be sent out from
the stump, the leaves formed on these shoots very often greatly exceed
the ordinary ones in dimensions. Such cases as this hardly come under
the head of malformations. But where one part only of the leaf is
excessively developed, the other portion remaining in its ordinary
condition, there can be no hesitation in ranking the phenomenon as
teratological.

Thus, Moquin says that the median nerve may be prolonged beyond the
blade of the leaf in the form of a short strap or ribbon-like
excrescence, while, at other times, the lateral parts of the leaf are
subjected to undue development. He refers to a case cited by
Schlotterbec[496] in which each side of the leaves of a yellow "violier"
(wallflower) was dilated into a kind of projecting lobe on either side
of the true apex of the leaf, thus rendering it in appearance
three-lobed. M. Delavaud[497] puts on record a case of hypertrophy in
the leaves of the common elm, resulting in the formation of an
additional lobe and a return to the tricostate type. A leaf so affected
is stated to have presented the appearance of a fusion of two leaves.
(See also Multiplication of leaves, p. 353.)

The hypertrophied and coloured leaf of _Gesnera_ occupying the place of
the absent inflorescence has been previously alluded to under the head
of displacement (p. 88).

In some instances hypertrophy is the opposite of suppression; as in the
case previously mentioned, where the stipule in the inflorescence of a
pea, which is usually undeveloped and rudimentary, was developed in the
form of a leafy cup or pitcher.

Another instance of the development of parts usually suppressed, is
afforded by the bud-scales of _Magnolia fuscata_, which may sometimes be
found with small but perfect leaves projecting from them, the leaf in
this case being the lamina which is ordinarily abortive, while the
scales are the representatives of the stipules. This condition is said
by Hooker and Thomson ('Flora Indica,' p. 73) to be constant in
_Magnolia Campbelli_.

=Enlargement of the perianth, &c.=--One or all the seg