rs, owing to the excessive multiplication of
petaloid stamens, the pistil is suppressed, in which cases it often
happens that the flower is depressed in the centre, as in some garden
varieties of _Ranunculus_. Schlechtendal, in describing a flower of
_Colchicum autumnale_, in which the perianth was virescent, says that,
although the stamens were present, the pistil was absent.

In proliferous flowers the pistil is often completely defective, its
place being occupied by the adventitious bud or axis.

As in other cases of like nature, suppression of the pistil is very
frequently consequent on fusion of flowers or other changes. Thus Morren
relates an instance of synanthy in the flowers of _Torenia scabra_,
accompanied by resorption or disappearance of some parts and spiral
torsion of others. The pistil was entirely absent in this instance.[484]

M. Gaetano Licopoli places on record an instance where the petals and
carpels of _Melianthus major_ were suppressed.[485]

On the whole, the pistil seems less subject to changes of this character
than the androecium.

Suppression of the pistil has been most frequently recorded in flowers
(normally bisexual) of--

Ranunculus!
Aconitium!
Delphinium!
Paeonia.
Caryophylleae!
Umbelliferae.
Trifolium repens.
hybridum.
Compositae, sp. pl.
Datura.
Torenia asiatica.
Colchicum autumnale.

=Suppression of ovules,--abortion of seeds.=--The two cases are taken
together, as the effects are similar, though it must be remembered that
in the one case the ovules at any rate have been formed, but their
development has been arrested, while in the other they have never
existed. The precise cause that has determined the absence of seed
cannot in all cases be ascertained in the adult condition, hence it is
convenient to treat the two phenomena under one head.

Many plants in other than their native climates either produce no fruit
at all, or the fruits that are produced are destitute of seed, _e.g._
_Musa_, _Artocarpus_, &c. Some of the cultivated varieties of the grape
and of the berberry produce no seeds.

Suppression or abortion of the seed is frequently associated with the
excessive development either in size or number of other portions of the
plant, or with an altered condition, as when carpels become foliaceous
and their margins detached. Hybridisation and cross fertilisation are
also well-known agents in diminishing the number and size of seeds.

=M