[78] 'Bull. Bot.,' pl. i, figs. 8-12.

[79] 'De Anthol.,' p. 37.

[80] Moquin, loc. cit., p. 305.

[81] 'Neue Denkschr. der Allg. Schweiz. Gesell.,' band v, pl. ii. p. 5.

[82] 'Hesperides,' auctore Ferrario. Rome, 1646, fig. 415, pp. 213 and 215. See also Michel, 'Traite du Citronnier.'

[83] 'Ann. des Science Nat.,' 3rd series, 1844, vol. i, p. 294.

[84] 'Org. Veget.,' vol. ii., p. 41.

CHAPTER III.

SOLUTION.

The isolation or separation of different whorls that are ordinarily adherent together is by no means of rare occurrence. Were it not that the isolation is often congenital, the word detachment would be an expressive one to apply to these cases, but as the change in question occurs quite as often from a want of union, an arrest or stasis of development, as from a _bona fide_ separation, the word solution seems to be, on the whole, the best. It corresponds in application to the word _liber_ (_calyx liber_, &c.), in general use by descriptive botanists.

As here employed, the term nearly corresponds with the "adesmie heterologue" of Morren. Moquin Tandon does not make any special subdivision for the cla.s.s of cases here grouped together, but places them all under "Disjonctions qui isolent les organes." It seems, however, desirable to have a separate word to express the converse condition of adhesion, and for this purpose the term solution, as above stated, is here employed. Diagrammatically, the condition may be expressed by placing a dotted line at the side of the letters thus:

: s s s s s : : c c c c c :

would indicate the disjunction of the sepals from the carpels (c), in contradistinction to adhesion, which may be represented by the unbroken line thus:

| s s s s s | | c c c c c |

=Solution of the calyx from the ovary.=--Of all the instances of adhesion which take place under ordinary circ.u.mstances, that between the calyx and the ovary is perhaps the most common. The _calyx adhaerens_ or _superus_ is a structural characteristic to which all botanists attach considerable importance; so that when exceptional cases occur in which the calyx becomes detached from the ovary, becomes, that is, _inferus_ or _liber_, a proportionate degree of interest attaches to the irregularity. It is not within the scope of the present work to inquire whether this detachment be real or merely apparent, arising from a want of union between parts ordinarily united together. This point must be left to the organogenists to decide in each particular case. So also the question as to what share, if any, the expanded and dilated flower-stalk may take in what are usually called inferior ovaries, can be here only incidentally touched upon.

Among _Rosaceae_, the change in question is very common, especially in conjunction with an elongation of the axis of the flower (apostasis) and with prolification, though it is by no means always co-existent with these malformations. When this alteration in the apparent relative position of calyx and carpels occurs in roses (_Rosa_) the appearances are generally such as to indicate that the "hip" of the rose is a dilatation of the peduncle, continuous above with the coherent bases of the sepals; this inference seems also to be borne out by what happens in the _Pomaceae_. In some cases in this sub-order, the calyx becomes detached from the carpels, so that the latter organs become more or less "superior," and distinct one from the other. This happens constantly in the double-flowered thorn, _Crataegus Oxyacantha_, in some blossoms of which the hollowed end of the peduncle still invests the base of the carpels, leaving the upper portions detached. In apples flowers are occasionally met with of greater size than usual and on longer stalks, so that the whole looks more like a rose than an apple blossom. In these cases it will usually be found that the calyx consists of distinct sepals, without a trace of the ordinary swelling beneath the flower. The petals are often more numerous than usual; the stamens variously changed, and the carpels sometimes absent; at other times, as in the instance figured in the adjacent woodcuts, figs. 36, 37, consisting of separate, superior ovaries, sometimes dest.i.tute of ovules, or, at other times, having two of these bodies.[85]

[Ill.u.s.tration: FIG. 35.--Proliferous Rose. Showing an absence of the usual dilatation of the flower-stalk, and other changes.]

This condition accords precisely with the account of the development of the flowers in _Pomaceae_ as given by Payer, Caspary, and others, so that the flowers above described would owe their deficiency of the swollen receptacle to an arrest of development. M. Germain de Saint Pierre, among other malformations of the rose, presented to the Botanical Society of France in 1854[86] two specimens which are of special interest as relating to this contested point. In the one, the swollen portion beneath the flower was surmounted by five perfect leaves, as, indeed, is not infrequent in such malformations; here, then, the calyx could have had little or no share in the production of the swelling in question. In the other, the swollen portion was actually above the insertion of the sepals here represented by five perfect leaves.

[Ill.u.s.tration: FIG. 36.--Section through Apple blossom, showing detachment of calyx from ovaries, absence of dilated flower-stalk, &c.]

[Ill.u.s.tration: FIG. 37.--Calyx detached from carpels in Apple.]

On the other hand, M. Planchon's specimen of the Quince before alluded to, not to mention other instances, tends to show that the bases of the sepals do sometimes enter into the composition of the pome. And, indeed, in many of these cases it would be impossible to say where the axial or receptacular portion ended, and the foliar portion began. As both from normal organogeny as well as from unusual conformation contradictory inferences may be drawn, it would obviously be unsafe to attempt the explanation of the so-called calyx-tube in general from any particular instances; so far as _Rosaceae_ are concerned, there is so much variation in the relative position of calyx and carpels under ordinary circ.u.mstances, that it is no matter for surprise that similar diversities should exist in teratological cases. A similar remark will apply to _Saxifragaceae_, _Cucurbitaceae_, _Myrtaceae_, _Bruniaceae_, _Rubiaceae_, and other families of like conformation.

[Ill.u.s.tration: FIG. 38.--Flower of _OEnanthe crocata_, in which the five sepals were completely detached from the ovaries, here three in number and dest.i.tute of stylopods.]

In _Umbelliferae_, a detachment of the calyx from the ovaries frequently occurs, sometimes without any other change; at other times attended by more serious alterations. So far as can be judged from exceptional occurrences of this kind, it would appear that in this order the axis or flower-stalk does not, in any material degree, enter into the composition of the fruit.

In the Rubiaceous genus _Bikkhia_, as mentioned by Duchartre, the ovary is completely inferior, but when the fruit arrives at maturity four small leaves are detached from its surface which had previously adhered to it, and which it seems reasonable to consider as the sepals.

In _Campanulaceae_ a similar separation of calyx from the ovary may be occasionally met with. On the other hand, the occasional formation of a leaf on the inferior ovary of those plants would indicate the axial nature of the fruit. In _Campanumaea_ and _Cyclodon_ the calyx is inferior, while the corolla is superior. In the last-named genus this peculiarity "is carried to the highest degree, the sepals being, in _C.

parviflorum_, placed on the peduncle of the flower far removed from the base of the corolla and ovary, whilst in _C. truncatum_ and in _Campanumaea_ they adhere to the base of the tube of the corolla."[87] In this order, then, as in _Saxifragaceae_, _Bruniaceae_, &c., no hasty conclusion should be drawn as to the nature of the fruit. In _Brunia microphylla_ the ovary is superior, enclosed within but not adnate to the cup-like calyx, to which latter, however, the petals and stamens are attached.

In _Onagraceae_ (_Jussieua_), as also in _Cactaceae_ (_Opuntia_), buds have been observed on the surface and edges of the inferior ovary.

Indeed, in the former genus, they have been produced artificially, but as buds may be formed on foliar as well as on axial organs, the fact cannot be made great use of in support either of the foliar or axial nature of the inferior ovary. In _Epilobium_, I have met with four perfect leaves at the summit of the ovary, in the place usually occupied by the sepals. This would also favour the notion that the axis entered into the const.i.tution of the fruit in this genus.

Mr. B. Clarke, in his 'New Arrangement of Phanerogamous Plants,' p. 4, cites a case wherein the perianth was completely detached from the surface of the ovary in _Cannabis sativa_.

It must be borne in mind that some of the recorded instances of change in the relative position of the calyx and pistil ought more properly to be referred to a subst.i.tution of carpels for stamens, as in _Begonia_, _Fuchsia_, &c. Among _Cucurbitaceae_, examples have been recorded, both of the detachment of the calyx from the ovary,[88] and of the partial conversion of some of the anthers of the male flower to carpels.

The very singular mode of germination of _Sechium edule_ in which the fruit, instead of rotting, becomes thickened into a kind of rhizome or tuber, is a fact that should not be overlooked in investigating the true nature of the fruit in this order.

The following are the genera in which the change has been most frequently observed:

*Rosa!

*Pyrus!

*Crataegus!

*Daucus!

Pastinaca.

Torilis.

Apium.

OEnanthe!

Heracleum, Athamanta.

Selinum.

Carum.

Imperatoria.

Rudbeckia!

*Campanula!

Lonicera!

Cuc.u.mis!

Cannabis.

=Solution of the stamens from the petals.=--A separation of the stamens from the petals in flowers, wherein those organs are usually adherent one to the other does not often occur unattended by other changes. It has been observed in _Cobaea scandens_ (Turpin), in _Antirrhinum majus_, and in many double flowers.

Partial detachment of the stamens from the styles occurs frequently in semi-double flowers of _Orchis_.[89]

FOOTNOTES:

[85] 'Gard. Chron.,' 1865, p. 554; 1867, p. 599.

[86] 'Bull. Soc. Bot. Fr.' 1854, p. 303.

[87] Hook et Thoms, 'Praecurs. ad Flor. Ind.,' Journ. Linn. Soc., vol.

ii, 1858, p. 6.

[88] Lindley, 'Veget. Kingd.,' p. 315.

[89] Masters, 'Journal of Linnean Society,' 1866, vol. viii, p. 207. On the subject of this chapter the reader should also consult Moquin-Tandon, 1. c., p. 298. Engelmann, 'De Antholysi,' p. 37, tab. v.

C. Morren, 'Bull. Acad. Belg.,' xix, part 3, p. 318. Cramer, 'Bildungsabweichungen,' p. 64. Fleischer, 'Missbild. Cultur. Pflanzen.'