360 SYMMETRY OF THE FLOWER.—SUPPRESSION. 
city of vegetable structure, that in the same flower the multipli- 
cation of organs should arise from two wholly different causes ; 
viz., alternation at one time, and unlining at another. 
‘3. As itis known that in some flowers, where the law of 
alternation usually obtains, the organs are occasionally placed 
opposite each other, it is necessary for the supporters of the un- 
lining theory to assume that in such a flower a part of the organs 
must be alternate and a part unlined, or at one time be all 
alternate and at another time be all unlined, which is entirely 
opposed to probability and sound philosophy. 
‘4, The examination of the gradual development of flowers, 
the only irrefragable proof of the real nature of final structure, 
does not in any degree show that the supposed process of unlin- 
ing has a real existence.’ 
According to Lindley’s view, therefore, whenever the organs 
of adjacent whorls are opposite to each other instead of alter- 
nate, this is supposed to arise from the suppression of a whorl 
which should be normally situated between the two that are 
present. ' 
3. SUPPRESSION OR ABORTION.— The suppression or abortion 
of parts may either refer to entire whorls ; or to one or more 
parts of a whorl. We shall treat this subject briefly under 
these two heads. 
a. Suppression or Abortion of one or more Whorls.—We have 
already stated that a complete flower is one which contains 
calyx, corolla, androecium, and gyncecium. When a whorl is 
suppressed, therefore, the flower necessarily becomes incomplete. 
This suppression may either take place in the floral envelopes ; 
or in the essential organs. At: 
Sometimes one whorl of the floral envelopes is suppressed, as 
in Chenopodiwm (fig. 29), in which case the flower is apetalows 
or monochlamydeous ; sometimes both whorls are suppressed, 
as in the common Ash (fig. 30), when the flower is waked or 
achlamydeous. 
When a whorl of the essential organs is suppressed, the 
flower is imperfect, as it then by itself cannot form seed. The 
androecium or gyncecium may be thus suppressed, in either of 
which cases the flower is wnisexwal ; or both andreecium and 
gyncecium may be suppressed, as in certain florets of some of 
the Composite, &c., when the flower is neuter. When the 
stamens are abortive, the flower is termed pistillate (fig. 35) ; 
or when the pistil is absent, staminate (figs. 34 and 503). 
The terms monecious, diwcious, and polygamous, which have 
reference to this point, have been already sufliciently explained 
(see page 241). 
Some botanists, as already noticed (page 358), consider that 
when the organs of adjacent whorls are opposite to each other 
instead of alternate, such an arrangement of parts arises from 
the suppression of an intermediate whorl; but this view is 
