ed from the connation of two
stipules which are ordinarily abortive.

Cohesion of the bracts by their edges, so as to form a tubular
involucre, or by their surfaces, so as to form a cupule, is not of
uncommon occurrence, under natural conditions, and may be met with in
plants which ordinarily do not exhibit this appearance.

=Cohesion of the sepals= in a normally polypetalous calyx renders the
latter gamosepalous, and is not of uncommon occurrence, to a partial
extent, though rarely met with complete. I have observed a junction of
the sepals to be one of the commonest malformations among Orchids,
indeed such a state of things occurs normally in _Masdevallia
Cypripedium_, &c. An illustration of this occurrence is given by Mr. J.
T. Moggridge in _Ophrys insectifera_, in 'Seemann's Journal of Botany,'
1866, p. 168, tab. 47. In Orchids, this cohesion of sepals is very often
co-existent with other more important changes, such as absence of the
labellum, dislocation of the parts of the flower, &c.

[Illustration: FIG. 11.--Gamopetalous flower of _Papaver bracteatum_.]

=Cohesion of the petals.=--Linnaeus mentions the occurrence of cohesion
of the petals in _Saponaria.[26]_ Moquin notices a Rose in which the
petals were united into a long tube, their upper portions were free and
bent downwards, forming a sort of irregular limb. An instance of the
polypetalous regular perianth of _Clematis viticella_ being changed into
a monopetalous irregular one, like the corolla of Labiates, is recorded
by Jaeger.[27] There is in cultivation a variety of _Papaver
bracteatum_, in which the petals are united by their margins so as to
form a large cup. Under normal circumstances, the petals become fused
together by their edges along their whole extent, at the base only, at
the apex only, as in the Vine, or at the base and apex, leaving the
central portions detached. Indications of the junction of the petals may
generally be traced by the arrangement of the veins, or by the notches
or lobes left by imperfect union. In Crocuses I have frequently met with
cohesion of the segments of the perianth, by means of their surfaces,
but the union was confined to the centre of the segment, leaving the
rest of the surfaces free.

=Cohesion of the stamens.=--Under natural circumstances, cohesion of the
stamens is said to take place either by the union of their filaments, so
as to form one, two, or more parcels (Monadelphia, Diadelphia,
Polyadelphia); at