y in 1809.[226]

The passage of ligulate to tubular corollas among _Compositae_ is not of
such common occurrence as is the converse change. I owe to Mr. Berkeley
the communication of a capitulum of a species of _Bidens_, in which
there was a transition from the form of ligulate corollas to those that
were deeply divided into three, four, or five oblong lobes. These then
were instances of regular peloria.

[Illustration: FIG. 121.--Flower of _Cattleya marginata_. Lip replaced
by a flat petal.]

In _Orchidaceae_ a similar change is not by any means infrequent; in a
few, indeed, a regular flower is the normal character, as in
_Dendrobium normale_, _Oncidium heteranthum_, _Thelymitra_, etc. Fig.
121, reduced from a cut in the 'Gardeners' Chronicle,' 1854, p. 804,
represents an instance of this kind in _Cattleya marginata_.

From the same journal the following account of a case of peloria in
_Phalaenopsis Schilleriana_ is also cited as a good illustration of this
peculiar change. The terminal flower differed entirely from all the
others; instead of the peculiar labellum there were three petals all
exactly alike, and three sepals also exactly alike; the petals resembled
those of the other flowers of the spike, and the upper sepal also; but
the two lower sepals had no spots, and were not reflexed as in the
ordinary way: thus, these six parts of the flower were all in one plane,
and being close together at their edges, made almost a full round
flower; the column and pollen-glands were unaffected. Professor
Reichenbach also exhibited at the Amsterdam Botanical Congress, of 1865,
a flower of _Selenipedium caudatum_ with a flat lip.

M. Gris[227] has placed on record some interesting cases of peloria of
this kind in _Zingiber zerumbet_; in the more complete forms the
androecium or staminal series was composed of six distinct pieces, the
three inner of which were fertile, while in the ordinary flower the
androecium is composed of two pieces, "a lip" and a fertile stamen.
"Is it not a matter of regret," says M. Gris, "to be obliged to call the
latter the normal flower?"

Under this head may likewise be mentioned those cases in which the
normal, or at least the typical symmetry of the flower is restored by
the formation of parts usually suppressed; thus Moquin cites an abnormal
flower of _Atriplex[228] hortensis_ described by M. Fenzl as having a
true calyx within the two bracts that usually alone encircle the
stamens. Adanson