alterations in the calyx and stamens, or sometimes as an isolated
occurrence. In the latter case it may be due to lateral chorisis, to
substitution, or to the development of organs usually suppressed; thus,
when in aconites we meet with four or five horn-like nectaries (petals)
instead of two only, as usual, the supernumerary ones are accounted for
by the inordinate development of parts which ordinarily are in an
abortive or rudimentary state only. This is borne out by what happens in
_Balsamineae_. In the common garden balsam the fifth petal is
occasionally present, while in _Hydrocera triflora_ this petal is always
present.

In a flower of a _Cyclamen_ recently examined there were ten petals in
one series, the additional five being evidently due to the subdivision
of the five primary ones; the natural circular plan of the flower was
here replaced by an elliptical one. A similar occurrence takes place in
the flowers of maples (_Acer_), which sometimes show an increased number
of parts in their floral whorls and an elliptical outline. Whether the
additional organs in this last case are the result of complete lateral
chorisis or of multiplication proper I do not know.

Orchids are very subject to an increase in the number of their labella.
As illustrations may be cited an instance recorded by Mr. J. T.
Moggridge in a flower of _Ophrys insectifera_, and in which there were
two labella without any other visible deviation from the ordinary
conformation.[400]

I am indebted to Mr. Hemsley for the communication of a similar specimen
in _O. apifera_, in which there were two divergent lips, each with the
same peculiar markings. One of the sepals in this flower was adherent to
one of the lateral petals. This augmentation of the labella depends
sometimes on the separation, one from the other, of the elements of
which the lip is composed, at other times on the development, in the
guise of lips, of stamens which are usually suppressed (see p. 380).

The following enumeration will suffice to show the genera in which an
increased number of petals or perianth-segments in any given whorl most
frequently occurs.

Anemone!
Ranunculus!
Aconitum!
Raphanus.
Bunias.
Saponaria.
Dianthus!
Pelargonium!
Hibiscus.
Fuchsia.
Sarothamnus!
Lotus!
Ulex!
Prunus!
Trifolium.
OEnanthe and Umbellif. pl.!
Sambucus!
Bryonia.
Campanula.
Solanum.
Veronica.
Cyclamen!
Primula!
Anagallis!