.

=Dialysis of the margins of individual foliar organs.=--In cases where
the leaf or leaf-like organ is ordinarily tubular or horn-like in form,
owing to the cohesion of its edges, it may happen either from lack of
union or from actual separation of the previously united edges, that the
tubular shape is replaced by the ordinary flattened expansion. Thus, in
_Eranthis hyemalis_, wherein the petals (nectaries) are tubular and the
sepals flat, I have met with numerous instances of transition from the
one form to the other, as shown in fig. 9, p. 24.

It is, however, in the carpels that this separation occurs most
frequently. When these organs appear under the guise of leaves, as they
often do, their margins are disunited, so that the carpel becomes flat
or open. This happens in the strawberry (_Fragaria_), the columbine
(_Aquilegia_), in _Trifolium repens_, _Ranunculus Ficaria_, &c.[76]

=Dialysis of the parts of the same whorl:--calyx.=--The separation of an
ordinarily coherent series into its constituent parts is necessarily of
more common occurrence than the foregoing. As here understood, it is the
precise converse of cohesion, and it may be represented diagrammatically
by a dotted line above the letters denoting the sepals, petals, &c. When
this change happens in the calyx we have the gamosepalous condition
replaced by the polysepalous one, as thus represented:

.............
S S S S S
instead of
_____________
S S S S S

as in a calyx of five coherent sepals.

Detachment of this kind occurs not unfrequently, as in _Primula
vulgaris_, _Trifolium repens_, &c. In _Rosaceae_ and _Pomaceae_ this
separation of the calyx is of the more moment, as it has reference to
the structure of the inferior ovary, as will be more fully mentioned
hereafter. Here, however, a case recorded by M. J. E. Planchon may be
alluded to[77] wherein a quince fruit (_Cydonia_) was surmounted by five
leaves, the surface of the pome being marked by as many prominences,
which apparently corresponded to the five stalks of the calycine leaves.
In this specimen, then, the inferior position of the ovary appeared to
be not so much due to an expansion of the fruit stalk, as to the fusion
of the hypertrophied stalks of the sepals. Some of the malformations
among Cucurbits point to a similar structure. It is probable that in
many of th