SYMMETRY OF THE FLOWER.—SUPPRESSION. 361 
manifestly insufficient to account for such a circumstance in all 
cases. Thus in the Rhamnacez (fig. 793), the stamens are 
opposite to the petals, and frequently united to them at the 
base, and We cannot but regard them as produced by transverse 
chorisis from the petals. In some cases, therefore, we regard 
the opposition of the parts of contiguous whorls to be due to 
suppression, and in others to chorisis. 
b. Suppression of one or more Organs of a Whorl.—This is a 
very common cause of deviation from normal structure ; we can 
here only bring forward a few examples. 
This suppression of parts is most frequent in the gyncecium. 
Thus in the Crucifere (jig. 794), we have four sepals, four 
petals, six stamens, and two carpels ; here two carpels are sup- 
pressed. In the Heartsease (jig. 797), we have a pentamerous 
re 7 97. Fia. 798. Fic. 799. 
Fig. 797. Diagram of the flower of the Heartsease-——Fig. 798. Diagram 
of a Leguminous flower.— Fig, 799. Diagram of the flower of Jmpatiens 
parviflora. 
flower, so far as the calyx, corolla, and andrcecium are con- 
cerned, but only three carpels, two carpels being here suppressed ; 
in Leguminous plants (fig. 798), we have five sepals, five petals, 
ten stamens, and only one carpel, four of the latter being here 
abortive ; in plants of the order Composit the calyx, corolla, 
and androecium have each commonly five organs, but only one, 
or, according to some botanists, two carpels. 
In seme species of Impatiens (fig. 799), we have five carpels, 
five stamens, and five petals, but only three sepals ; here two 
sepals are suppressed ; in Tropxolum pentaphyllum (fig. 800), 
there are five sepals, and but two petals, three of the latter 
organs being here abortive. In the Labiatz and Scrophulariaceze 
one of the stamens is commonly suppressed, and sometimes 
three ; thus in the Lamiwm we have five parts to the calyx 
and corolla, but only four stamens ; and in the Salvia we have 
also five parts to the calyx and corolla, but only two perfect 
stamens. 
The abortion of whorls and parts of a whorl is well illus- 
trated by plants of the Euphorbiacez, and the following diagram 
