Vegetable Teratology | Page 5

besides important papers of Turpin, Geoffroy
de Saint Hilaire, Brongniart, Kirschleger and others, to which frequent

allusion is made in the following pages, there is the classic work of
Moquin-Tandon, which was translated into German by Schauer.
Germany has also given us the monographs of Batsch, Jæger, Roeper,
Engelmann, Schimper, Braun, Fleischer, Wigand, and many others.
Switzerland has furnished the treatises of the De Candolles, and of
Cramer; Belgium, those of Morren, &c., all of which, as well as many
others that might be mentioned, are, with the exception of
Moquin-Tandon's 'Eléments,' to be considered as referring to limited
portions only and not to the whole subject.[1]
In the compilation of the present volume great use has been made of the
facts recorded in the works just cited, and especially in those of
Moquin-Tandon, Engelmann, and Morren. A very large number of
communications on teratological subjects in the various European
scientific publications have also been laid under contribution. In most
cases reference has been given to, and due acknowledgment made of,
the sources whence information has been gathered. Should any such
reference be omitted, the neglect must be attributed to inadvertence, not
to design. In selecting illustrations from the immense number of
recorded facts, the principle followed has been to choose those which
seemed either intrinsically the most important, or those which are
recorded with the most care. In addition to these public sources of
information, the author has availed himself of every opportunity that
has offered itself of examining cases of unusual conformation in plants.
For many such opportunities the author has to thank his friends and
correspondents. Nor has he less reason to be grateful for the
suggestions that they have made, and the information they have
supplied. In particular the writer is desirous of acknowledging his
obligations to the Society, under whose auspices this work is published,
and to Mr. S. J. Salter, to whom the book in some degree owes its
origin.
The drawings, where not otherwise stated, have been executed either
from the author's own rough sketches, or from the actual specimens, by
Mr. E. M. Williams. A large number of woodcuts have also been kindly
placed at the disposal of the author by the proprietors of the 'Gardeners'
Chronicle.'[2]

As it is impossible to frame any but a purely arbitrary definition of
teratology or to trace the limits between variation and malformation, it
may suffice to say that vegetable teratology comprises the history of
the irregularities of growth and development in plants, and of the
causes producing them. These irregularities differ from variations
mainly in their wider deviation from the customary structure, in their
more frequent and more obvious dependence on external causes rather
than on inherent tendency, in their more sudden appearance, and lastly
in their smaller liability to be transmitted by inheritance.
What may be termed normal morphology includes the study of the
form, arrangement, size and other characteristic attributes of the several
parts of plants, their internal structure, and the precise relation one form
bears to another. In order the more thoroughly to investigate these
matters it is necessary to consider the mode of growth, and specially
the plan of evolution or development of each organ. This is the more
needful owing to the common origin of things ultimately very different
one from the other, and to the presence of organs which, in the adult
state, are identical or nearly so in aspect, but which nevertheless are
very unlike in the early stages of their existence.[3] Following Goethe,
these changes in the course of development are sometimes called
metamorphoses. In this way Agardh[4] admits three kinds of
metamorphosis, which he characterises as: 1st. Successive
metamorphoses, or those changes in the course of evolution which each
individual organ undergoes in its passage from the embryonic to the
adult condition, or from the simple and incomplete to the complex and
perfect. 2. Ascending metamorphoses, including those changes of form
manifested in the same adult organism by the several parts of which it
consists--those parts being typically identical or homologous, such as
the parts of the flower, or, in animals, the vertebræ, &c. 3. Collateral
metamorphoses, comprising those permutations of form and function
manifested in homologous organs in the different groups of organisms,
classes, orders, genera, species, &c.
Thus, in the first instance, we have a comparative examination of the
form of each or any separate part of the same individual at different
epochs in its life-history; in the second we have a similar comparison

instituted between the several parts of the same organism which
originally were identical in appearance, but which have in course of
evolution altered in character. In the third form we have the
comparative view not of one organ at different times, nor of the several
parts of one organism, but of the