[332] Seemann's 'Journ. Bot.,' iv, p. 168, tab. 47, f. 1.

[333] Moquin-Tandon, l. c., 220, _Pa.s.siflora_. Masters, 'Journ. Linn.

Soc.,' 1857, p. 159, _Saponaria_. Seemann's 'Journ. Botany,' vol. iii, p. 107, _Narcissus_.

[334] 'Bull. Soc. Bot. Fr.,' 1857, p. 452.

[335] 'Gardeners' Chronicle,' 1866, p. 897.

[336] Maout, 'Lecons Element.,' vol. ii, p. 488.

[337] Poiteau and Turpin, 'Arb. Fruit,' t. 37, and Trecul, 'Bull Soc.

Bot. France,' vol. i. p. 307.

[338] Clos, 'Mem. Acad. Toulouse,' 5 ser., vol. iii.

[339] 'Bot. Zeit.,' 1850, t. viii, pp. 514, 664. 'Flora,' (B. Z.) 1832, t. xv, p. 252; also cited in 'Ann. des Serres et des jardins,' vi, pp.

241-5. See also Schlechtendal, 'Bot. Zeit.,' 1845, t. 3, p. 6.

[340] 'Bull. Soc. Bot. France,' t. viii, p. 453.

[341] See also Allmann, 'Rep. Brit. a.s.soc.,' July, 1851.

[342] 'Theory of Horticulture,' ed. 2, p. 82.

[343] 'Mem. Soc. Hist. Nat. Paris.' i, 16.

[344] Gen. Munro, 'Trans. Linn. Soc.,' xxvii, p. 7.

[345] 'Bull. Soc. Bot. Fr.,' 1857, p. 21.

[346] 'Ann. Scienc. Nat.,' t. viii, 1837, p. 50, and 'Bot. Zeit.' (R.), 1836, t. xix, p. 513, &c. See also MM. Sourd Dussiples and G. Bergeron, 'Bull. Soc. Bot. France,' viii, p. 349; Von Schmidel, 'Icon. plant. et a.n.a.l. part.' 1782, p. 210, fig. 54.

[347] G.o.dron, 'Bull. Soc. Bot. Fr.,' xiii, p. 82, Rev. Bibl.

[348] Cited in Henfrey, 'Bot. Gazette,' iii, p. 12.

[349] 'Ann. Nat. Hist.,' September, 1856, p. 56. See also Kirschleger, 'Flora (Bot. Zeit.),' xxiv, 1841, p. 340, _Salix alba_. Henschel, 'Flora (Bot. Zeit.),' 1832, t. xv, p. 253, _S. cinerea_. Hartmann, 'Flora (Bot.

Zeit.),' xxiv, p. 199, _S. nigricans_. Meyer, C. A., 'Bull. Phys.

Math.,' t. x, _S. alba_.

PART IV.

HETEROMORPHY.

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 degree, but absolutely. This is often the case when disease or injury affects the plant; for instance, in the case of galls arising from insect-puncture the structure is rather a new growth altogether, than dependent on mere hypertrophy of the original tissues.

These absolute deformities arising from the causes just mentioned belong rather to pathology than to teratology strictly so called; but, under the head of deformities, may be mentioned sundry deviations not elsewhere alluded to.

CHAPTER I.

DEFORMITIES.

The special meaning here attached to the term deformity is sufficiently explained in the preceding paragraph; it remains to give a few ill.u.s.trations, and to refer to other headings, such as Heterotaxy, Hypertrophy, Atrophy, &c., for malformations capable of more rigid cla.s.sification than those here alluded to.

[Ill.u.s.tration: FIG. 166.--Portion of the under surface of a cabbage-leaf, with horn-like excrescences projecting from it.]

=Formation of tubes.=--The production of ascidia or pitchers from the cohesion of the margins of one or more leaves has been already alluded to (see pp. 21, 30), but there is another cla.s.s of cases in which the tubular formation is due, not so much to the union of the margins of a leaf as to the disproportionate growth of some portions as contrasted with others, whence arises either a depressed cavity, as in the case of a leaf, or an expanded and excavated structure, when the stem or some portion of it is affected.

The fruit of the rose, the apple, the fig, and many others, is now generally admitted to be composed externally of the dilated end of the flower-stalk in which the true carpels become imbedded. Between such cases and that of a peltate leaf with a depressed centre, such as often occurs, to some extent, in _Nelumbium_, there is but little difference.

In cabbages and lettuces there not unfrequently occurs a production of leaf-like processes projecting from the primary blade at a right angle (see Enation). Sometimes these are developed in a tubular form, so as to form a series of little horn-like tubes, or shallow troughs, as in _Aristolochia sipho_. At other times the nerves or ribs of the leaf project beyond the blade, and bear at their extremities structures similar to those just described.

[Ill.u.s.tration: FIG. 167.--Lettuce leaf, bearing on the back a stalked cup, arising from the dilatation of the stalk (?).]

In a variety of _Codiaeum variegatum_ a similar formation may be seen to a minor extent. Even the common _Scolopendrium vulgare_ occasionally produces small pitchers of this character, as in the varieties named _perafero-corautum_, Moore, and _peraferum_, Woll.[350]

In carnations leaves may sometimes be seen from both surfaces, from which project long, sharp-pointed tubular spurs at irregular intervals.

A very singular ill.u.s.tration of this is figured by Trattinick,[351], in which the leaves, epicalyx, sepals, and petals, were all provided with tubular spurs.

In _Cephalotus follicularis_ rudimentary or imperfect pitchers may be frequently met with, in which the stalk of the leaf is tubular and bears at its extremity a very small rudimentary leaf-blade. It is not in all cases easy to trace the origin and true nature of the ascidium, as the venation is sometimes obscure. If there be a single well-marked midrib the probability is that the case is one of cohesion of the margins of the leaf; but if the veins are all of about equal size, and radiate from a common stalk, the pouch-like formation is probably due to dilatation and hollowing of the petiole. Again, when the result of a union of the margins of the leaf, the pitcher is generally less regular than when formed from the hollowed end of a leaf-stalk. Further information is especially needed as to the mode of development and formation of these tubular organs, so as to ascertain clearly when they are the result of a true cupping process, and when of cohesion of the margins of one or more leaves. (See Cohesion, p. 31. For bibliographical references consult also A. Braun, 'Flora v. Bot. Zeit.,' 1835, t. xviii, p. 41, _Aristolochia_.)

=Tubular formations in the flower.=--A similar formation of tubes happens in some double flowers; for instance, it is not infrequent in double flowers of _Primula sinensis_, in which tubular petal-like structures are attached to the inner surface of the corolla; sometimes these petaloid tubes replace the stamens, while at other times they appear to have no relation to those organs. In the particular flowers now alluded to the tubular form seems due to a dilatation, and not to a cohesion of the margins. (See Cohesion, p. 23.) These tubular petals resemble in form and colour almost precisely the normal corolla in miniature, but are not surrounded by a calyx, nor do they contain stamens, while the less perfect forms show clearly their origin from a single tube-like organ.

[Ill.u.s.tration: FIG. 168.--Corolla of _Primula sinensis_ turned back to show a tubular petal springing from it. One only is shown for the sake of clearness; they are generally numerous.]

The formation of spurs or spur-like tubes in a quasi-regular manner has been spoken of under the head of Irregular Peloria, p. 228, but we occasionally meet with tubular processes which seem to occur in an irregular manner, and to have no reference to the symmetrical plan of the flower, and which are due probably to the same causes as those which induce hypertrophy. Such spurs have frequently been seen on the corolla of _Digitalis purpurea_, _Antirrhinum majus_,[352] _Tulipa Gesneriana_, and occasionally on the sepals of _Fuchsia_. They are very frequent in some seasons in the corolla of certain calceolarias (_C. floribunda_).

By Morren this production of advent.i.tious spurs was called "Ceratomanie."

[Ill.u.s.tration: FIG. 169.--Corolla of _Calceolaria_, showing irregular tubular spurs projecting from the lower lip.]

Similar processes may sometimes be seen in the capsules of _Linaria vulgaris_, as also in the fruits of some of the Solanums, quite without reference to the arrangement of the carpels, so that their production seems to be purely irregular.

Morren, as previously remarked, gave the name "Solenaidie" to tubular deformities affecting the stamens, a term which has not been generally adopted; the deformity in question is by no means of uncommon occurrence in some double or partially pelorised flowers, as _Antirrhinum_, _Linaria_, &c. A similar formation of conical out-growths may frequently be met with in the fruits quite irrespectively of any disjunction of the carpels.

=Contortion.=--An irregular twisting or bending of the stem or branches is by no means of uncommon occurrence, the inducing causes being often some restriction to growth in certain directions, or the undue or disproportionate growth in one direction, as contrasted with that in another. Hence it may arise from insect-puncture, parasitic growth, or any obstacle to the natural development. Frequently it exists in conjunction with fasciation, the ends of the branches being curved round like a shepherd's crook, from the growth on one side being so much greater than on the other. Sometimes it is a mere exaggeration of a normal condition; thus, in what are termed flexuose stems the stem twists alternately to one side or another, frequently in a.s.sociation with an oblique form of the leaf. This state is sometimes present to an extreme degree, as in some varieties of shrubs (_Crataegus_, _Robinia_, &c.) cultivated for their singularly tortuous branches.

[Ill.u.s.tration: FIG. 170.--Portion of the culm of a _Juncus_, bent irregularly.]

[Ill.u.s.tration: FIG. 171.--Portion of a branch of _Crataegus oxyacantha_, var. _tortuosa_.]

Such cases as those just mentioned, however, are but slightly irregular compared to others in which the deformity exists to such an extent that the traces of the ordinary mode of growth are almost obliterated. M.