dinary circumstances are wholly suppressed, so that the morphological
structure of the flower, at first a matter of theory, becomes actually
realised. Fig. 156 is a diagram showing the presence of two additional
labella within the ordinary one in a species of _Catasetum_, and
representing two petaloid stamens, thus evidently completing the outer
staminal whorl, of which there is usually but a single representative
(see Peloria, Multiplication, Prolification). In some of these double
orchids it is, however, necessary not to confound a petaloid condition
of the existing column with the development of usually suppressed
stamens in a petaloid form. Thus, in _Lycaste Skinneri_ the column is
frequently provided with two petal-like wings, which might readily be
supposed to be two stamens of the inner whorl adherent to the column; a
little attention, however, to the relative position of these
adventitious wings is generally sufficient to enable the observer to
ascertain the true nature of the appearance.[306]

[Illustration: FIG. 156.--Diagram of flower of _Catasetum_, with two
labella.]

Some forms of duplicate or hose in hose corollas are apparently due, not
so much to the formation of a second corolla within the first, as to the
presence of an inner series of petal-like stamens, which, by their
cohesion, form a second pseudo-corolla within the first. The staminal
nature of this pseudo-corolla is inferred from the occasional presence
of anthers on it.[307] In _Datura fastuosa_, as well as in _Gloxinia_, a
pseudo-corolla of this kind sometimes occurs with the addition of a
series of petaloid stamens attached to its outer surface.[308]

When the petalody specially affects the anther-lobes, as in _Arbutus_,
_Petunia_, _Fuchsia_, _&c._, the venation of the petal-like portion is
very frequently laminar, thus tending to show that the anther is in
such cases really a modification of the blade of the leaf; but as, on
the other hand, we often find petal-like filaments bearing pollen-sacs
on their sides, it is clear that we must not attribute the formation of
pollen to the blade of the leaf only, but we must admit that it may be
formed in the filament as well.[309]

[Illustration: FIG. 158.--Portion of a double columbine (_Aquilegia_),
showing petalody of the connective.]

[Illustration: FIG. 159.--Petaloid stamens, _Hibiscus_.]

Petalody of the connective is of less frequent occurrence than the
corresponding change in the other