AN ACCOUNT OF THE PRINCIPAL DEVIATIONS FROM THE USUAL CONSTRUCTION OF PLANTS BY MAXWELL T. MASTERS, M.D., F.L.S. WITH NUMEROUS ILLUSTRATIONS BY E. M. WILLIAMS. LONDON: PUBLISHED FOR THE RAY SOCIETY BY ROBERT HARDWICKE, 192. PICCADILLY. MDCCCLXIX. TO JOSEPH DALTON HOOKER, M.D., D.C.L., LL.D., F.R.S., F.L.S., ETC. ETC. DIRECTOR OF THE ROYAL GARDENS, KEW, This Volume IS GRATEFULLY INSCRIBED....

The union of parts, usually separate in their adult condition, is of very common occurrence as a malformation. The instances of its manifestation admit of being grouped under the heads of Cohesion, where parts of the same whorl, or of the same organ, are united together; and of Adhesion, where the union takes place between members of different whorls, or between two or more ordinarily wholly detached and distinct parts. In either case, the apparent union may be congenital (that is, the result of

Under this head are included all those instances wherein organs usually entire, or more or less united, are, or appear to be, split or disunited. It thus includes such cases as the division of an ordinarily entire leaf into a lobed or partite one, as well as those characterised by the separation of organs usually joined together. Union, as has been stated in a previous chapter, is the result either of persistent integrity or of a junction of originally separate organs, after their formation; so

Necessarily connected with changes in the arrangement of organs are similar alterations in their position; so closely, indeed, that but for convenience sake, it would be unnecessary to treat them separately. There are, however, some anomalous developments affecting the relative position of organs that could hardly be treated of under any of the preceding paragraphs. There are, also, certain rare instances where an organ is not so much displaced as misplaced; that is to say, it is developed on or

Deviations from the ordinary form of organs arising from stasis or arrest of development are included under this heading. 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, p

Most irregular flowers owe their irregularity to an unequal development of some of their organs as compared with that of others. When such flowers become exceptionally regular they do so either because development does not keep pace with growth, and a regular flower is thus the result of an arrest of the former process (regular peloria), or because the comparatively excessive development, which usually occurs in a few parts is, in exceptional cases manifested by all, hence the flower becomes reg

Much of the objection with which Goethe's famous essay on the 'Metamorphosis of Plants' was met on its publication may be traced to a misapprehension of the sense in which Goethe employed the word. As used by him, it had nearly the same signification as now applied to the word development by organogenists. It does not necessarily imply that there has been a change in any particular organ, but rather that there has been, to some extent, a change in the plan of construction, in accordance with whi

There are certain malformations that have little in common beyond this, that they cannot readily be allocated in either of the great groups proposed by writers on teratology. There are also deformities which, unlike the majority of deviations from the ordinary structure, are absolute and not relative. While the latter are due to an exaggeration, or to an imperfection of development, or, it may be, to a partial perversion in organization, the former differ from the normal standard, not merely in

An augmentation in the number of parts may arise from several causes, and may sometimes be more apparent than real. True multiplication exists simply as a result of over-development; the affected organs are repeated sometimes over and over again each in their proper relative position, and without any transmutation of form. Metamorphy, on the other hand, often gives rise to the impression that parts are increased in number, when it may be that the stamens and pistils, one or both, are not so much

A diminution in the number of parts is generally due to suppression, using that word as the equivalent of non-development. It corresponds thus in meaning with the Fehlschlagen of the Germans, the avortement complète of Moquin and other French writers. It differs from atrophy, or partial abortion, inasmuch as the latter terms apply to instances wherein there has been a partial development, and in which evolution has gone on to a certain extent, but has, from some cause or other, been checked. The

The term hypertrophy may serve as a general one to comprise all the instances of excessive growth and increased size of organs, whether the increase be general or in one direction merely. General hypertrophy is more a variation than a deformity, unless indeed it be caused by insect puncture or the presence of a fungus, in which case the excessive size results from a diseased condition. For our present purpose hypertrophy may be considered as it affects the axile or the foliar organs, and also ac

Under the head of atrophy are included those cases wherein the organs affected are actually present, but in a dwarfed and stunted condition as compared with surrounding parts. The diminished size is, in such instances, obviously due to a partial development and to an arrest of growth at a certain stage, from the operation of various causes, either external or inherent to the organization itself. It may affect any part of the plant, and exists, in very varying degree, in different instances, bein

During the progress of the foregoing pages through the press, several additional illustrations of particular malformations have come under notice. Some of the more important of these may here be recorded. Fasciation ( see p. 11 ).—The following plants may be added to the list:— Acer eriocarpum , Arabis albida , Brassica oleracea , var., Guarea , sp., Artabotrys sp. In all, with the exception of the first-named, the fasciation occurred in the inflorescence. In some species of Artabotrys , indeed,

The reader is requested to make the following corrections:— Page 182. Fig. 94 should be 94*. Page 194. The reference 3 applies not to the nutmeg but to the hop, figured at p. 193 . Page 309. Fig. 165 legend—for Sempervivun tecotorum read Sempervivum tectorum . PRINTED BY J. E. ADLARD, BARTHOLOMEW CLOSE. Page xx and 202 : 208. Passage of pinnate to palmate leaves in horse-chesnut 439 'chesnut may be old spelling for chestnut?'. Changed as most are spelled chestnut. Page 65 : Naturforscherversamml