urious instance of this kind in the branches of _Pinus_.
'Regel. Garten Flora,' vol. 8, tab. 268.

[11] 'Bull. Soc. Bot. France,' 1860, p. 881.

[12] Ibid., 1861, p. 708.

[13] Ibid., 1860, p. 923.

[14] 'Proc. Linn. Soc.,' April 5, 1853.

[15] 'Organ. Veget.,' pl. iii, fig. 1.

[16] 'Bull. Acad. Roy. Bruxelles,' t. xviii, p. i and p. 591.

[17] 'Linnaea,' tom. 13, p. 383.

[18] 'Verhandl. Nat. Hist. Vereins,' 1859, Bonn, tom. xvi, tab. 3.

[19] 'Bull. Soc. Bot. Fr.,' vol. i, p. 62.

[20] 'Report of Internat. Bot. Congress,' London, 1866, p. 131, tab.
vii, figs. 10-13.

[21] 'Bull. Acad. Roy. Belg.,' t. xviii, 2nd part, p. 179.

[22] D. C., 'Organ. Veget.,' pl. xvii, fig. 3, and pl. xlviii, fig. 2.

[23] 'Mem. Acad. Toulouse,' 1862.

[24] Bonnet, 'Recherches Us. feuill.,' pl. xxi, fig. 2.

[25] De Candolle, 'Mem. Leg.,' pl. v, fig. 14.

[26] 'Phil. Bot.,' Sec. 125.

[27] 'Nov. Act. Acad. Nat. Cur.,' 14, p. 642, t. xxxvii.

[28] 'Journal of the Linn. Soc. Bot.,' vol. iv, p. 55.

[29] 'Bull. Acad. Roy. Bruxelles,' 1838, t. v, p. 582. 'Bull. Acad. Roy.
Belg.,' 1852, t. xix, part iii, p. 437.

CHAPTER II.

ADHESION.

Adhesion, so called, occurs either from actual union of originally
distinct members of different whorls or from the non-occurrence of that
separation which usually takes place between them. It is thus in some
degree a graver deviation than cohesion, and is generally a consequence
of, or at least is coexistent with, more serious changes; thus if two
leaves of the same whorl are coherent the change is not very great, but
if two leaves belonging to different whorls, or two leaves in the same
spiral cycle are adherent, a deformation in the axis or a certain amount
of dislocation must almost necessarily exist. Adhesion as a normal
occurrence is usually the result of a lack of separation rather than of
union of parts primitively separate. Instances of adhesion between
different organs is seen under ordinary circumstances in the bract of
the Lime tree, which adheres to the peduncle, also in _Neuropeltis_,
while in _Erythrochiton hypophyllanthus_ the cymose peduncles are
adherent to the under surface of the leaf.

Adhesion between the axes of the same plant is sufficiently treated of
under the head of Cohesion, from which it is in this instance impossible
to make a distinction. Adhesion of the inflorescence is necessarily a
frequent accompaniment of fasciation and cohesion of the br