J. J. Simpson 
255 
VI. Variation in the Gyn^cium. 
So far we have not considered the gynseciuni on account of the small number 
of variations which occur in that organ and from the fact that these do not lend 
themselves to statistical treatment. 
The gynjBcium consists typically of two carpels which are flattened in a vertical 
plane parallel to those containing the pairs of stamens in the inner whorl ot the 
androecium. The thin partition wall separating the two carpels therefore stands 
at right angles to this plane. 
Now when we examine the different types of variations in the structure and 
number of the carpels we find the following: (1) a single carpel, (2) two carpels 
(typical), (3) three carpels, (4) four carpels, (5) two sets of two carpels within 
a single perianth, (6) two sets of two carpels within separate perianths but on one 
pedicel. 
Let us now proceed to examine each of these in some detail. 
(1) The gynoBcium consists of a single carpel (see Figs. LXXXVII— XCII). 
In all these ca.ses, except LXXXVII, as will be at once seen by reference to the 
figures, the suppression of a carpel is accompanied by the suppression of some of 
the members of nearly all the other organs thus : 
In LXXXVIII two petals are absent and one stamen is aborted. 
In LXXXIX one sepal, two petals and two stamens are absent. 
In XC, XCI and XCII all the organs are deficient in members. 
A noteworthy phenomenon in this respect also is that the suppression of 
members which accompanies the suppression of a carpel is usually in the vertical 
plane which passes through the plane of separation of the carpels. 
(2) The gyncecium consists of two carpels. 
This is the accepted typical structure and the statistical study deals with these 
in detail. 
(3) The gyncecium consists of three carpels (see Figs. XCIII and CII). 
When three carpels occur in the gyna3cium they are never found co-laterally, 
i.e. the additional carpel is never found with its origin at the side of a carpel, but 
always arising from the plane of separation, which is in the plane of greatest 
variability. 
(4) The gyncecium consists of four carpels (see Fig. CI). 
Just as in the previous case the increase in the number of carpels takes place 
in the plane of separation of the carpels — one on either side, so that a cruciate 
structure is found. A reference to Fig. CI will make this clear. In both of these 
groups it will be evident that an increase in the female reproductive organs is 
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