Without studying the mode of development, it is not in all cases possible to tell under which of the above categories any particular instance should be placed; hence, in the following sections, except where otherwise stated, the cases are grouped according to the appearance presented in the adult condition, rather than to the way in which the changes from the typical condition are brought about. With reference to the foliar organs it is necessary to distinguish those cases in which there is, from any cause, an augmentation in the number of component parts of a whorl, from those in which the increase takes place in the numbers of the whorls themselves.
FOOTNOTES:
[376] Braun, 'Pringsheim Jahrbuch f. Wiss. Bot.,' 1858, 1, p. 307, tab. 22, 23.
[377] Henfrey, 'Jour. Linn. Soc. Bot.,' vol. iii, p. 159.
[378] On the subject of chorisis or dédoublement the reader may profitably consult Moquin-Tandon, 'Ess. sur les Dédoublements,' and the same author in 'Ann. Sc. Nat.,' t. xxvii, p. 236. and 'El. Ter. Veget.,' p. 337. Dunal, 'Consid. Org. Fleur.,' Montpell., 1829, p. 32, note 3. A. de St. Hilaire in 'Ann. Sc. Nat.,' ser. 3, t. iii, p. 355, adnot. Lindley, 'Elements of Botany,' p. 76. Asa Gray. 'Botanical Text Book.'
CHAPTER I.
MULTIPLICATION OF AXILE ORGANS, INFLORESCENCE, ETC.
By Linné an undue number of branches was designated as "plica," from the analogy with the disease of the hair known as plica polonica: "Plicata dicitur planta, cum arbor vel ramus excrescit minimis intertextis ramulis, tanquam plica polonica ex pilis, ceu instar nidi Picæ, quod vulgo a genio ortum arbitratur; frequens apud nos in Betula, præsertim Norlandiæ, in Carpino Scaniæ, nec infrequens in Pinu."[379]
By some of the older authors this condition was called polyclady. In some cases, it would seem to be due to fungi as in the witches' brooms (hexenbesen) of the German forests; in other instances, it is a result of mutilation as after the operation of pollarding.
Moquin-Tandon[380] mentions a case in a grafted ash in the botanic garden of Toulouse, where below the graft there was a large swelling, from which proceeded more than a thousand densely-packed, interlacing branches.
This must have been similar to the condition so commonly met with in the birch, and frequently in the hornbeam and the thorn, and which has prompted so many a schoolboy to climb the tree in quest of the apparent nest. It is probable that some of the large "gnaurs" or "burrs," met with in elms, &c., also in certain varieties of apples, are clusters of adventitious buds, some of which might, and sometimes do, lengthen out into branches.