Vegetable Teratology | Page 7

with other and often compensatory
changes. Hence it is often necessary, in studying any given
malformation, to refer to two or more subdivisions, and in this way a
certain amount of repetition becomes unavoidable. The details of the
several cases of malformation given in these pages are generally
arranged according to their apparent degree of importance. Thus, in a
case of prolification associated with multiplication of the petals, the
former change is a greater deviation from the customary form than the
latter, hence reference should be made, in the first instance, to the
sections treating on prolification, and afterwards to those on
multiplication. To facilitate such research, numerous cross references
are supplied.
In the investigation of teratological phenomena constant reference must
be made to the normal condition, and vice versâ, else neither the one
nor the other can be thoroughly understood. It cannot, however, be
overlooked that the form and arrangement called normal are often
merely those which are the most common, while the abnormal or
unusual arrangement is often more in consonance with that considered
to be typical than the ordinary one. Thus, too, it is often found that the
structural arrangements, which in one flower are normal, are in another
abnormal, in so far that they are not usual in that particular instance.

For purposes of reference, a standard of comparison is required; and
this standard, so long as its nature is not overlooked, may, indeed must
be, to some extent, an arbitrary one. Thus in the phanerogamous plants
there is assumed to exist, in all cases, an axis (stem, branches, roots,
thalamus, &c.), bearing leaves and flowers. These latter consist of four
whorls, calyx, corolla, stamens, and pistils, each whorl consisting of so
many separate pieces in determinate position and numbers, and of
regular proportionate size. A very close approach to such a flower
occurs normally in Limnanthes and Crassula, and, indeed, in a large
proportion of all flowers in an early stage of development. To a
standard type, such as just mentioned, all the varied forms that are met
with, either in normal or abnormal morphology, may be referred by
bearing in mind the different modifications and adaptations that the
organs have to undergo in the course of their development. Some parts
after a time may cease to grow, others may grow in an inordinate
degree, and so on; and thus, great as may be the ultimate divergences
from the assumed standard, they may all readily be explained by the
operation, simply or conjointly, of some of the four principal causes of
malformation before alluded to. The fact that so many and such varied
changes can thus readily be explained is not only a matter of
convenience, but may be taken as evidence that the standard of
reference is not wholly arbitrary and artificial, but that it is a close
approximation to the truth.
It has already been said that an arrangement like that here considered as
typical is natural to some flowers in their adult state, and to a vast
number in their immature condition. It would be no extravagant
hypothesis to surmise that this was the primitive structure of the flower
in the higher plants. Variations from it may have arisen in course of
time, owing to the action of an inherent tendency to vary, or from
external circumstances and varied requirements which may have
induced corresponding adaptations, and which may have been
transmitted in accordance with the principle of hereditary transmission.
This hypothesis necessarily implies a prior simplicity of organisation,
of which, indeed, there is sufficient proof; many cases of malformation
can thus be considered as so many reversions to the ancestral form.

Thus, teratology often serves as an aid in the study of morphology in
general, and also in that of special groups of plants, and hence may
even be of assistance in the determination of affinities. In any case the
data supplied by teratology require to be used with caution and in
conjunction with those derived from the study of development and
from analogy. It is even possible that some malformations, especially
when they acquire a permanent nature and become capable of
reproducing themselves by seed, may be the starting-point of new
species, as they assuredly are of new races, and between a race and a
species he would be a bold man who would undertake to draw a hard
and fast line.[7]
Discredit has been cast on teratology because it has been incautiously
used. At one time it was made to prove almost everything; what
wonder that by some, now-a-days, it is held to prove nothing. True the
evidence it affords is sometimes negative, often conflicting, but it is so
rather from imperfect interpretation than from any intrinsic
worthlessness. If misused the fault lies with the disciple, not with
Nature.
Teratology as