nless it be to state
that the horizontal line--is intended to indicate the cohesion of the
parts over which it is placed, while the vertical line | signifies the
adhesion of the organs by whose side it is placed. The formula

S S S S S
------------------------
| P P P P P
|
| ST ST ST ST ST

shows that the sepals (S) are distinct, the petals (P) coherent, and the
stamens (ST) adherent to the petals.

[3] Wolff was the first to call attention to the great importance of the
study of development. He was followed by Turpin, Mirbel, Schleiden,
Payer, and others, and its value is now fully recognised by botanists.

[4] Agardh, "Theoria Syst. Plant.," p. xxiii.

[5] In the memoirs of Hopkirk, Kirschleger, Cramer, Hallier, and others,
malformations are arranged primarily according to the organs affected,
an arrangement which has only convenience to justify it. It is hoped
that the index and the headings to the paragraphs in the present volume
will suit the convenience of the reader as well as if the more
artificial plan just alluded to had been adopted.

[6] Cryptogamous plants are only incidentally alluded to in these pages,
owing to their wide difference in structure from flowering plants.
Attention may, also, here be called to a paper of M. de Seynes in a
recent number of the Bulletin of the Botanical Society of France, vol.
xiv, p. 290, tab. 5 et 6, in which numerous cases of malformation among
agarics are recorded. See also same publication, vol. iv, p. 744; vol.
v, p. 211; vol. vi, p. 496.

[7] On this subject see a paper of M. Naudin in the 'Comptes Rendus,'
1867, t. 64, pp. 929-933.

[8] It is probable that many terms and expressions calculated to mislead
in the way above mentioned are made use of in the following pages. The
inconsistency manifested by their use may be excused on the ground of
ignorance of the true structure, and by the circumstance that in many
cases facts alone are recorded without an explanation of them being
offered. Moreover, it is desirable to act in conformity with the usual
practice of botanical writers, and not to change established
terminology, even if suspected to convey false ideas, until the true
condition of affairs be thoroughly well ascertained by organogenetic
research or other means.

[9] A curious illustration of the latter class of alterations came under
the writer's notice last summer (1868), and which