hich the
fruit is composed. The portion near the peduncle was binary, while the
distal extremity of the fruit was ternary. The main difficulties
attending the acceptance of this explanation reside in the peculiar
reversed position of the leaf, and in the fact that the fruit of the
_Cucurbitaceae_ is probably of axial nature, the dilated and succulent
end of the peduncle adhering to and usually concealing the carpels; in
some cases, however, these latter project beyond the axial portion,
leaving no doubt as to the true nature of the structure in these
particular instances.

Admitting the axial nature of the fruit, it might be supposed that in
Mr. Salter's cucumber an adventitious leaf had been given off from the
axis, but even on that supposition the reversed position offers a
difficulty, and there still remains to be explained the fact that the
proximal part of the fruit was binary in its constitution, the distal
end ternary.

M. Norman[264] mentions a case wherein the carpels of _Anchusa
ochroleuca_ were replaced by two leaves; from this he draws the
inference that the pistil of borages and labiates is really composed of
two leaves, placed fore and aft, the margins of the leaves being
congenitally fused. This tallies well with the account given of the
development of these plants by Payer, Germain de St. Pierre, and others.

In an Indian species of _Triumfetta_, not only were the petals
virescent, but the ovary also was much enlarged, and in some flowers it
was divided half way down into five lanceolate leaves (fig. 139), the
sepals and stamens being in their normal condition.

In the preceding instances the foliaceous condition has pervaded the
entire pistil, or at any rate the basal portion or ovary, and it may be
noticed that the ovary is thus shown to consist in some cases of the
sheath of the leaf, as in _Aquilegia_; in other cases of the blade, as
in _Cerasus_, _Daucus_, &c.

[Illustration: FIG. 139.--Flower of _Triumfetta_, sp., carpels
represented by five leaves.]

There are cases, however, in which a part only of the pistillary
structure thus becomes foliaceous. Linnaeus, 'Prolepsis,' Sec. 9,
mentions some flowers of _Carduus heterophyllus_ and _C. tataricus_ in
which the style had grown into two green leaflets, and in which the calyx
and corolla were also leaf-like. A very singular instance is recorded by
Baillon,[265] wherein the pistil of _Trifolium repens_ consisted of
three carpels, either separate