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136 of its own legitimate form as a portion of the flower, but has received some unusual stimulation which has given it a tendency to develope itself into an entire flower, the moss-like appendages being possibly imperfect rudiments of stamens (2). At the point of development at which these deformed and imperfect stamens have been produced in the form of a moss-like excrescence on the calyx, it would seem that the unnatural growth ceases, and the legitimate process prevails, so that the petals of the flower are duly developed within the monstrosity that has taken the place of the usual calyx.

This aberration, whatever be its hidden cause, must have taken place, originally, on some single branch of a common double rose; but, as every bud on each distinct branch is acted upon by the same specific vital principle, the aberrating branch being taken off and caused to strike root would become an independent plant, every new branch of which would produce buds having the same vital principles as those of the original branch; and so a distinct variety would be established, which might be multiplied to any extent, every flower of which would have the curiously deformed growth of calyx from which the name of the now common moss-rose is derived.

The multiplied petals of the double flower itself are forms of monstrosity which affords a still more direct illustration of the principle that flowers are but developed leaves, as leaves are rudimental flowers, as may be easily shown; and in this case the manner of the transformation is not merely conjectured, as in the preceding case, but can be proved to demonstration. Under ordinary circumstances, and in the greater number of plants, the flowering process occurs when the growth of a branch is stopped by the partial exhaustion of the supply of sap. Its further power of elongation being thus withheld, and additional growth being impeded, preparations for the production of seeds commence, from which the plant, or rather a new plant, may recommence its course of existence and reproduction. These preparations for the production of seeds lead to the commencement of the transformation of leaves (or rather the buds or germs of leaves), into calyx, stamens, pistils, and petals. But peculiar disturbing causes occasionally divert the system of transformation from its proper course, and instead of the central portion of the leaf-germs forming themselves into pistil and stamens, and the surrounding leaf-germs into petals and calyx, the whole of the leaf-germs that should have formed various parts of the flower, become petals only, and thus is produced that luxuriant and beautiful monstrosity, that double flower, the ancient glory of gardens, the large double rose.

An interesting illustration of the theory of leaf-transformation often occurs in an unhealthy state of the double-flowered stock. In double varieties of the Brompton, or ten week stock, most amateur gardeners must have observed a peculiar growth that is occasionally developed from some disturbing cause, such as injudicious removal, or unusual degree of cold; or, the development of the flowers at too late a period of the season. Under the influence of any of these causes of disturbance to the habit of the plant, a disposition is shown in the additional petals to return to their normal condition of leaves; and then occurs the interesting spectacle, of a flower composed of leaves instead of petals (3).

The calyx is seldom so much diverted from its usual form as to be rendered unfit to perform its office as the cup or socket of the flower, or of its frequent office as seed vessel. The reason of this is, that in its original form it is probably the husk of the leaf-bud, as in a different stage of the growth of the plant it becomes the husk of the flower. The calyx does, however, sometimes disappear in the aberrations of the transformative processes, as in the double cowslip, in which it is represented by perfect petals; or rather a perfect petal, deeply divided at regular distances; which is the characteristic of the whole primrose tribe, being a monopetalous or single petaled family. From this calyx transformed to a petal issues the real floral petal, presenting the curious aspect, not of a double flower, but of one single flower issuing from another single flower. In this case, the inner flower is fertile, having its full complement of pistil and stamens, and a more or less perfect seed vessel. Examples of this kind of doubleness rarely, if ever, occur except in monopetalous flowers, such as the primrose, or bell flowers, of which the well-known old garden favourites, the double pipped oxlip and the double Canterbury bell, may be cited as garden examples. These monopetalous plants do not, however, always exhibit the peculiar kind of doubleness formed by the development of one pip within another, which generally occurs by the