eveloped only, and forming a kind of cup, from which the true carpels
protrude.

=Abortion of the leaves.=--Arrest of growth in the leaves occurs in
different ways; sometimes the whole leaf is smaller than usual; at other
times certain parts only are reduced in size; while, in a third class of
cases, portions of the leaf are entirely suppressed.

Moquin[526] mentions having seen the leaves of _Chenopodium vulvaria_,
and of _Diplotaxis muralis_ reduced to a fourth of their natural size;
and he alludes to other cases of the same nature, seen by other
observers, in _Hypericum perforatum_ and _Blitum polymorphum_.

_Nicandra physaloides_[527] has also been met with in a similar
condition, which, indeed, is a common result of insect-puncture, and of
fungous growth in plants. Those instances in which the leaf is
diminished in size, without any attendant malformation in other organs,
may be regarded rather as variations than as monstrosities, as in the
case of the entire-leaved varieties of those plants which ordinarily
have cut or divided leaves, _e.g._ _Plantago Coronopus_, var.
_integrifolia_, _Papaver Rhoeas integrifolia_, &c. &c. The same remark
may be made of those specimens in which one part of the leaf is
developed to a less extent than another, as happens in the submerged
leaves of such plants as _Ranunculus aquatilis_, _Cabomba aquatica_, the
spiney leaves of _Berberis_, the fenestrated leaves of _Ouvirandra_, &c.
In the illustrations last cited the relative deficiency of one portion,
as contrasted with another, takes place as a constant occurrence, and is
uniform and regular throughout the whole leaf. When, on the other hand,
the deficiency in question happens accidentally and irregularly, the
change may be considered as a malformation. One side of the blade of the
leaf is frequently affected in this manner, the other portions remaining
unaffected. It would appear as if any plant might be thus altered, but
the following species appear to be particularly subject to this change:
_AEesculus Hippocastanum_, _Digitalis purpurea_, _Morus alba_, _Fagus
silvatica contracta_ (hort.), _Codiaeum variegatum_ var. _erosum_
(hort.), _Broussonettia papyrifera_, _Scolopendrium vulgare_, &c.

Frequently this irregular diminution in proportion is coexistent with an
unusual degree of cleavage or laciniation of the margin, as in _Acer
platanoides laciniatum_, _Tilia asplenifolia_, _Alnus imperialis_
(hort.), _Fagus silvatica_ var. (