Petalody of the ovules.—The principal changes which occur in the ovule have already been alluded to at pp. 262–272; it may here be stated, however, that the ovules are occasionally represented by small stalked petal-like structures. This happens with especial frequency among Cruciferæ.[313]

Petalody of the accessory organs.—A petaloid condition of the disc, of the scales, or other excrescences from the axis or from the lateral portions of the flower, is of frequent occurrence, though it is but rarely that the change is of any great importance in a morphological point of view. C. Morren has given the name adenopetaly to a case wherein one of the glands at the base of the petals in Lopezia was replaced by a petal.[314] A similar change may be seen in the double Oleander.

Staminody of the bracts.—An instance of this has been already alluded to in Abies excelsa, as observed by Prof. Dickson, and in which some of the bracts were seen assuming the form and characteristic of the stamens see ante: p. 192. Signor Licopoli met with a similar substitution of anthers for bracts in Melianthus major.[315]

Staminody of the sepals and petals.—In the first named this is of very rare occurrence. M. Gris has recorded an instance in Philadelphus speciosus[316] which appears to be the only case on record. The corresponding change in the case of the petals is far more common. De Candolle cites in illustration of this occurrence flowers of the common haricot, in which the alæ and carina of the corolla were thus changed.[317] There is in cultivation a form of Saxifraga granulata wherein the petals are replaced by stamens, so that there are fifteen stamens. A similar change has been observed in Capsella bursa-pastoris.

Cramer figures and describes a stamen occupying the place of a petal in Daucus Carota.[318] Turpin[319] describes a similar occurrence in Monarda fistulosa, in which the lower lip terminated in an anther, but this may have been a case of adhesion. Moquin cites from Chamisso, Digitalis purpurea, and from Jussieu, Asphodelus ramosus, as having presented this change, and Wiegmann[320] has seen anthers developed on the awns of Avena chinensis. In semi-double flowers of Ophrys aranifera and Orchis mascula, the lateral petals are occasionally partially antheroid, and others occur in which two of the outer series of stamens, which are ordinarily suppressed, are present, but in a petaloid state. Reichenbach[321] figures an illustration of this change, and also Moggridge.[322]

Staminody of the pistils.—The existence of this change has been denied by several authors, nevertheless, it is of sufficiently common occurrence. Alexander Braun notices the transformation of pistils into stamens in Chives (Allium Scorodoprasum), and in which three stamens appeared in the place of as many pistils, and had extrorse anthers, while the six normal anthers are introrse. In the horse-radish (Armoracia rusticana), two of the carpels are frequently converted into stamens, while two other organs absent from the normal flower make their appearance as carpels. Roeper has observed this phenomenon in Euphorbia palustris,[323] and in Gentiana campestris.[324] In these examples one of the carpels was apparently absent, and its place supplied by an anther. Roeper has also mentioned a balsam with a supernumerary stamen occupying exactly the position of a carpel.[325]

Agardh has observed a similar thing in a hyacinth, one half of the fruit of which contained seeds, and the other half, anthers. B. Clarke mentions an instance in Mathiola incana in which the carpels were disunited, and antheriferous at the margin.[326]

The passage of pistils to stamens in willows has been frequently remarked, as in Salix babylonica, silesiaca, cinerea, Caprea and nigricans. One of the most curious illustrations of this transformation in this genus is given by Henry and Macquart (Erst. Jahrb. des bot. Vereines am m. et n. Rhein., 1837). In the flowers in question the series of changes were as follows:—first, the ovary opened by a slit, and then expanded into a cup; next, anther-cells were developed on the margin of the cup, with stigmas alternating with them, the ovules at the same time disappearing; lastly, the margin became divided, and bore three perfect anthers, which in the more perfect states were raised on three filaments.

Campanula persicifolia, C. rapunculoides, and C. glomerata have been observed to present an anther surmounting the pistil.[327] Double tulips often present this change, and a like appearance has been observed in Galanthus nivalis, and Narcissus Tazetta.

Moquin mentions the existence of this condition in a female plant of maize, some of the pistils of which were wholly or partially converted into anther-like organs. Mohl has recorded an analogous malformation in Chamærops humilis, and in which the three carpels were normally formed, and only differed from natural ovaries in this, that along the two edges of the ventral suture there was a yellow thickening, which a cross section of the ovary showed to be an anther-lobe filled with pollen.[328]

In Tofieldia calyculata a similar substitution of a stamen for a carpel has been observed by Klotsch,[329] and Weber[330] gives other instances in Prunus and Pæonia. Corresponding alterations may be met with in cultivated tulips, in the cowslip and other plants. In most of the above cases the transmutation has been perfect, but in quite an equal number of cases a portion only of the carpel is thus changed, generally the style or the stigma; thus Baillon describes the stigmas of Ricinus communis as having been in one instance antheriferous.[331] Moggridge figures a flower of Ophrys insectifera in which the rostellate process was replaced by an anther.[332]

Mohl remarks that the change of pistils into stamens is more common in monocarpellary pistils than it is in those which are made up of several carpels. It seems clear that in this transformation the lobes of the anther and the development of pollen have no relation to the production of ovules.

Staminody of the accessory organs of the flower.—The scales that are met with in some plants, either as excrescences from the petals, or as imperfect representatives of stamens or other organs, are occasionally staminoid; thus the scales of Saponaria officinalis, of Silene, Nerium Oleander, the rays of Passiflora, the corona of Narcissus, have all been observed occasionally to bear anthers.[333] In the case of Narcissus the loose spongy tissue of the corona seems to have the nearest analogy to the anther-lobes, while the prolonged connective is more like the ordinary segments of the perianth in texture. The species in which this change may most frequently be observed are, N. poeticus, N. incomparabilis, and N. montanus.

M. Bureau found in some flowers of Antirrhinum majus two petal-like bodies standing up in front of, or opposite to the two petals of the upper lip,[334] and similar developments in which each of the two adventitious segments are surmounted by an anther may be met with frequently. It does not follow because these organs bear anthers that they are morphologically true stamens. They are really scales, &c., taking on themselves accidentally the characters proper to stamens.

Pistillody of the perianth.—The passage of the segments of the perianth into carpels has been observed frequently in Tulipa Gesneriana, the change in question being generally attended by a partial virescence. M. Gay is said by Moquin to have observed a flower of Crocus nudiflorus in which the segments of the perianth were cleft and fringed at the same time, so that they presented the appearance of the stigmas.

Pistillody of the sepals.—In some double flowers of the garden pea communicated by Mr. Laxton, among other peculiarities was a supernumerary 5–6-leaved calyx, some of the segments of which were of a carpellary nature, and bore imperfect ovules on their margins, while at their extremities they were drawn out into styles.[335]

Pistillody of the stamens.—This change whereby the stamens assume more or less the appearance of pistils is more commonly met with than is the metamorphosis of the envelopes of the flower into carpels. In some cases the whole of the stamen appears to be changed, while in others it is the filament alone that is altered, the anther being deficient, or rudimentary; while, in a third class of cases, the filament is unaffected, and the anther undergoes the change in question. In those instances in which the filament appears to be the portion most implicated, it becomes dilated so as to resemble a leaf-sheath rather than a leaf-stalk, as it does usually.

One of the most curious cases of this kind is that recorded in the 'Botanical Magazine,' (tab. 5160, f. 4) as having occurred in Begonia frigida already alluded to, and in which, in the centre of a male flower, were four free ovoid ovaries alternating with as many stamens. In the normal flowers of this plant, as is well known, the male flowers have several stamens, while in the female flowers the ovary is strictly inferior, so that, in the singular flower just described, the perianth was inferior instead of being superior, as it is usually. It should be added also that the perianth in these malformed flowers was precisely like that which occurs ordinarily in the male flowers.

In some varieties of the orange, called by the French "bigarades cornues," the thalamus of the flower, which is usually short, and terminated by a glandular ring-like disc, is prolonged into a little stalk or gynophore, bearing a ring of supernumerary carpels. These carpels are isolated one from another, and are formed by the transformation of the filaments of the stamens.[336]

The additional carpels in the case of the apple of St. Valéry, in which the petals are of a green colour, like the sepals, are by some attributed to the transformation of the stamens into carpels. These adventitious carpels frequently contain imperfect ovules and form a whorl above the normal ones. (See Pyrus dioica of Willdenow.)[337] A similar change occasionally happens in the stamens of Magnolia fuscata, while in double tulips this phenomenon is very frequent, and among them may be found all stages of transition between stamens and pistils, and many of the parts combining the characters of both.[338] Dunal and Campdera have described flowers of Rumex crispus, with seven pistils, occupying the place of as many stamens.

In Papaver bracteatum a considerable number of the stamens sometimes become developed into pistils, especially those which are nearest to the centre of the flower, and in these flowers the filaments are said to become the ovaries, while the anthers are curled so as to resemble stigmas. A similar change is not infrequent Papaver somniferum. Goeppert, who found numerous instances of the kind in a field near Breslau, says the peculiarity was reproduced by seed for two years in succession.[339] Wigand ('Flora,' 1856, p. 717) has noticed among other changes the pistil of Gentiana Amarella bearing two sessile anthers. Polemonium cæruleum is another plant very subject to this change. Brongniart[340] describes a flower of this species in which the stamens were represented by a circle of carpels united to each other so as to form a sheath around the central ovary. By artificial fertilization M. Brongniart obtained fertile seeds from the central normal ovary as well as from the surrounding metamorphosed stamens.

Cheiranthus Cheiri has long been known as one of the plants most subject to this anomaly. De Candolle even mentions it in his 'Prodromus' as a distinct variety, under the name of gynantherus. Brongniart (loc. cit.) thus refers to the Cheiranthus:—"Sometimes these six carpellary leaves are perfectly free, and in this case they spread open, presenting two rows of ovules along their inner edges, or these edges maybe soldered together, forming a kind of follicle like that of the columbine; at other times, these staminal pistils are fused into two lateral bundles of three in each bundle, or into a single cylinder which encircles the true pistil. In a third set of cases these outer carpels are only four in number, two lateral and two antero-posterior, all fused in such a manner as to form around the normal pistil a prism-shaped sheath, with four sides presenting four parietal placentæ, corresponding to the lines of junction of the staminal carpels."

In the accompanying figures (fig. 163, a-d) the nature of this change is illustrated. In some of the specimens it is easy to see that the two shorter stamens undergo the change into carpels later and less perfectly than the four longer ones, and not infrequently the outer pair are altogether absent. In most of the flowers of this variety the petals are smaller and less perfectly developed than usual.[341]

In Lilium tigrinum, some specimens of which were gathered by Mr. J. Salter, in addition to various degrees of synanthy and other changes, some of the stamens were developed in the form of carpels, adherent by their edges so as to form an imperfect tube or sheath around the normal pistil. Fig. 164 shows one of the intermediate organs from these flowers, in which half the structure seems devoted to the formation of ovules, while the other half bears a one-celled anther. Lindley[342] has also described a case of this kind in a species of Amaryllis.

In Saxifraga crassifolia it sometimes happens that mixed with the stamens, and originating with them, are a number of distinct and perfectly formed carpels, wholly separated from the normal carpels, in the centre of the flower. In this particular instance there is usually no intermediate condition between the stamen and the pistil. Guillemin[343] also describes a transformation of the stamens into carpels in Euphorbia esula.

When the anther is involved it may be only partially so, or almost the whole organ may be transformed. As instances of very partial change may be cited the passage of the connective into a stigma in Thalictrum minus, or the passage of the points of the anthers into imperfect styles in some species of bamboo.[344]

In Rosa arvensis similar transformations have been observed of a slightly more complex character than those just mentioned, and passing into more important changes, especially to the formation of pollen within ovules, formed on the edges of an open carpellodic anther (see p. 186).

Mr. Berkeley has recorded an analogous case in a gourd in which the stamens bore numerous ovules (p. 200), and Baillon describes another gourd in which certain fleshy appendages surrounding the andrœcium were provided with ovules.[345]

Payer, in his 'Organogénie,' p. 38, mentions a stamen of Dionæa bearing not only an anther, but likewise an ovule.

Sempervivum tectorum and S. montanum, have long been noticed as being very prone to present this change. Mohl[346] remarks that, in the transformation of the stamens to the pistil in the common houseleek, the filament of the stamen generally preserves its form, the anthers alone undergoing change. At other times, however, the transformation takes place at the same time, both in the filament and in the anther. When the stamens are numerous some of them remain in their normal state, while others, and especially the inner ones, undergo a change. Sometimes all the stamens are changed simultaneously, while at other times some of these organs may be found in which the anther is partially filled with ovules, and partially with pollen.

In the accompanying figures (fig. 165, a-h) a series of intermediate stages is shown between the ordinary stamen of Sempervivum tectorum and the ordinary carpel, from which it will be seen that the filament is little, if at all, affected, and that in those cases where there is a combination of the attributes of the stamen and of the pistil in the same organ the pollen is formed in the upper or inner surface of the leaf-organ, while the ovules arise from the opposite surface from the free edge, (b, c, d, e, f, g).

In a drawing made by the Rev. G. E. Smith of a malformed flower of Primula acaulis, and which the writer has had the opportunity of examining, the stamens are represented as detached from the corolla, and their anthers replaced by open carpels, with ovules arising, not only from their edges, but also from their surfaces, while the apex of the carpellary leaf was drawn out into a long style, terminated by a flattened spathulate stigma.

Delphinium elatum is one of the plants in which this change has been most frequently noticed.[347]

In willows the change of pistils into staminal organs has been frequently observed. In Salix babylonica Prof. Schnizlein has described various transition stages between the carpels and the stamens, and in one instance, in addition to this change, a perfect cup-shaped perianth was present, as happens normally in Populus[348]. Mr. Lowe also records the conversion of stamens into ovaries in Salix Andersoniana, and this by every conceivable intermediate gradation.[349]

The following list will serve to show what plants are most subject to this anomaly. It is difficult to draw any accurate inference from this enumeration, but attention may be called to the frequency of this occurrence in certain plants, such as the Sempervivum, the wallflower, the poppy, and the heath. Why these plants should specially be subject to these changes cannot be at present stated.

By the student of animal physiology such a change as above described—equivalent to the substitution of an ovary or a uterus for a testis—would be looked on as next to impossible; the simpler and less specialised structure of plants renders such a change in them far more easy of comprehension.

Pistillody of the ovule.—An instance of this extraordinary transformation in the carnation, as observed by the Rev. Mr. Berkeley, is given at p. 268.

PART IV.
HETEROMORPHY.

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 illustrations, and to refer to other headings, such as Heterotaxy, Hypertrophy, Atrophy, &c., for malformations capable of more rigid classification than those here alluded to.