anches.

=Adhesion of foliar organs= may occur either between the margins or
between the surfaces of the affected parts; in the former case there is
almost necessarily more or less displacement and change of direction,
such as a twisting of the stem and a vertical rather than a horizontal
attachment of the foliar organ to it; hence it generally forms but a
part of other and more important deviations.

=Adhesion of leaves by their surfaces.=--The union of leaves by their
surfaces is not of very frequent occurrence, many of the instances cited
being truly referable to other conditions. Bonnet describes the union of
two lettuce leaves, and Turpin that of two leaves of _Agave americana_,
in which latter the upper surface of one leaf was adherent to the lower
surface of the leaf next above it, and I have myself met with similar
instances in the wallflower and in lettuce and cabbage leaves; other
instances have been mentioned in _Saxifraga_, _Gesnera_, _&c._[30]

In these cases, owing to the non-development of the internodes, the
nascent leaves are closely packed, and the conditions for adhesion are
favorable, but in most of the so-called cases of adhesion of leaf to
leaf by the surface, a preferable explanation is afforded either by an
exuberant development (hypertrophy) or by chorisis (see sections on
those subjects). Thus, when a leaf of this kind is apparently so united,
that the lower surface of one is adherent to the corresponding surface
of another, the phenomenon is probably due rather to extra development
or to fission. There is an exception to this, however, in the case of
two vertically-erect leaves on opposite sides of the stem; here the two
upper or inner surfaces may become adherent, as in an orange, where two
leaves were thus united, the terminal bud between them being suppressed
or abortive.

Adhesion between the membranous bract of _Narcissus poeticus_ and the
upper surface of the leaf is described by Moquin.[31] The same author
mentions having seen a remarkable example of adhesion in the involucels
of _Caucalis leptophylla_, the bracts of which were soldered to the
outer surface of the flowers. M. Bureau[32] mentions an instance
wherein the spathe of _Narcissus biflorus_ was partially twisted in such
a manner that the lower surface of its median nerve was adherent to the
corresponding surface of one of the sepals, mid-rib to mid-rib, thus
apparently confirming a law of G. de Hilaire, that when two parts o