rue corolla.]

A still more singular case is that of a variety of the Gloxinia,
described originally by Professor Edouard Morren,[521] but which is now
becoming common in English gardens. When first observed these flowers
were observed to produce petaloid segments outside the ordinary corolla,
and partially adherent to (or rather, not completely separated from it)
much as in the azalea before mentioned, the outer surface being brightly
coloured, like the inner surface of the corolla in ordinary gloxinias.
Being encouraged and tended by gardeners, in course of time, instead of
a series of petalodes, more or less distinct from one another, a second
corolla or "catacorolla" was formed outside the primary one, so that a
hose in hose flower was produced, but, in this case, the supplementary
flower was formed on the outside and not within the ordinary corolla.
Moreover, the disposition of the colour was reversed, for in the
outermost corolla the richest hues were on the outer surface, while in
the inner or true corolla they were on the inside.

Professor Morren considers the adventitious petalodes as rudiments of so
many supplementary flowers, axillary to the calyx, and adnate to the
corolla; each lobe then would, in this view, represent an imperfect
flower, and the completed catacorolla would be formed of a series of
confluent flowers of this description. But this view involves the
assumption of the suppression of all the parts of the flower, except the
lobes in question.

[Illustration: FIG. 214.--"Catacorolla" of _Gloxinia_, formed from the
union of adventitious petalodes on the outside of the true corolla
(after Morren).]

The view here propounded that the lobes in question are enations from
the true petals, which become confluent, so as to form the catacorolla,
is surely more simple, involves no assumptions of suppression of parts;
and moreover, is borne out by the examination of some flowers, where the
production of these adventitious lobes from the outside of the minute
partially developed petals could be distinctly seen.

=Enation from the stamens.=--An illustration of this process occurred in
some double-flowered rhododendrons, which presented the following
arrangement of parts:--calyx and corolla normal; within the latter eight
petal-like stamens, forming a pseudo-corolla. The appearance presented
by the petaloid filaments and anthers was as if they were adnate to the
centre of the petals, but, on closer examin