Vegetable Teratology: An Account of the Principal Deviations from the Usual Construction of PlantsMasters, Maxwell T. (Maxwell Tylden)
Science
Vegetable Teratology: An Account of the Principal Deviations from the Usual Construction of Plants
Masters, Maxwell T. (Maxwell Tylden)
Plants -- Abnormalities
There are many cases in which the forms proper to a juvenile condition
of the plant are retained for a much longer period than ordinary, or
even throughout the life of the individual growth goes on, but
"development" is checked. Such conditions may even be propagated by seed
or bud. It is a very general thing for botanists to consider these cases
as reversions to a simpler, primitive type, and this may be so; but on
the other hand, they may be degenerations from a complex type, or they
may have no direct relation to any antecedent condition. Stasimorphic
changes affecting principally the relative size of organs--such, for
instance, as the non-development of internodes, or the atrophy or
suppression of parts will be found mentioned in the sections relating to
those subjects. In the present part those alterations which affect the
form of organs principally are treated of.
FOOTNOTES:
[219] [Greek: Stasis-morphosis].
CHAPTER I.
PERSISTENCE OF JUVENILE FORMS.
The retention in adult life of a form characteristic of an early stage
of development, and therefore usually transient, may be manifested in
any of the organs of the plant. As these cases are for the most part
treated under separate headings, it is here only necessary to allude to
a few, which it is difficult to allocate satisfactorily, while the
reader may be referred for other instances of like nature to the
sections on Peloria, Atrophy, Suppression, Dimorphy, Substitutions, &c.
[Illustration: FIG. 115.--_Juniperus sinensis_. Two forms of leaves on
branches of the same shrub.]
=Stasimorphy in the leaves of conifers.=--In many conifers the leaves
produced in the young state of the plant are different, both in
arrangement and form, from those subsequently developed (see pp. 89,
90). But it occasionally happens that the plant continues to form
throughout its existence leaves such as are usually produced only in a
young state; thus M. Gubler ('Bull. Soc. Bot., Fr.,' vol. viii, 1861, p.
527) describes a plant of _Pinus pinea_ in which the primordial, usually
transitory, foliage was permanent, leaves of the ordinary shape not
being developed at all. It more often happens that some only of the
leaves retain their young form while others assume other shapes, see
fig. 115. This happens frequently in the larch and constantly in the
Chinese juniper when it has arrived at a considerable age. In _Cupressus
funebris_ two forms of leaves may often be found on the same plant, the
one representing the juvenile state, the other the more developed
condition. What is very singular, is that a cutting taken from the
branch with leaves of the young form grows up into a shrub bearing
leaves of no other shape, so that an ordinary observer unacquainted with
the history of the plant would imagine that he had to deal with two
distinct species. This fact is the more interesting when compared with
the alternation of generations which takes place among the lower
animals.
Public-domain text, read in full here on John Shaqi.
Reviews
Reviews
No reviews yet
Be the first to share your thoughts on this work.
Elsewhere in the archive
Join the Discussion
Join the discussion
Sign in to leave a comment or review.
Sign InorCreate an account