Form, considered absolutely, possesses a double origin of beauty; its two branches being, as in so many instances, in apparent contrast with each other - and these two branches are Unity and Variety.

And these should be always combined, and the rather because the combinations they admit of are unlimited; nor is it necessary that either branch should be considered more essential than the other, but in proportion as in any flower or variety the value of one is increased, the other may recede and give way without being entirely obliterated; as in flowers of the disc or of the cupped form, unity is the leading property; in the composite forms, as the Fuchsia or the lxia, variety takes the lead.

By Unity is meant the singleness of idea presented to the mind, whereby the impression becomes definite and clear, not being distracted by contending claims, nor divided among many: as a cup formed of petals in contradistinction to six equal and separate petals, without the combining and controlling idea of a cup.

When applied to an outline, it means the appearance when that outline is one and unbroken, as in the circular form of a Petunia.

Its contrary is produced - In idea, when a flower consists of a plurality of like and equal parts not uniting to form one idea, and especially if those parts are circular, as in the Veronica. In outline, 1. By the occurrence of an interval; either by a breach of continuity in the substance, as in the flower of the Arum, causing an effect like the loss of a guard-leaf in a Carnation: or by a separation between the parts which compose it, as in the petals of the Night-scented Stock. To this may be referred the broken edging in a Picotee, and broken lacing in a Pink.

2. Or by an abrupt change: either of kind; from a straight line to a curve, or from a curve to a straight line, as in the Pea-blossom: or of direction, as when two straight lines terminate in a point, as in the pointed petals of the Narcissus. By variety, when combined with unity (for simply considered, it needs no explanation), is meant the comprising many ideas under one - that the unity is not a dry unit.

When applied to an outline, it means the appearance when the line is flowing and continuous, yet constantly changing; such as is a curve, as in the circular blossom of the Convolvulus: or a succession of segments of curves, themselves arranged in a curve in the same plane, as in the flat circle composed of lobes in the Phlox or the Verbena: or in the more complicated outline composed of curves and lines in different planes, as in the Fuchsia.

When applied to the contents of an outline, it again explains itself, and is fulfilled when all is not same or self, but varied with diverse forms and colours.

Now with regard to the influence which these two sources of beauty exercise upon our judgments. First, with respect to Unity.

If an external outline be broken, one or more of these three effects will be produced: either it will convey an idea of imperfection, that something is defective, and needs to be filled up; as in the native Pansy, or much more in an inferior cultivated variety, in which the improvement is begun, but only to the extent of making the defect more glaring by shewing how it may be removed.

Or, if the parts are equal and similar, as in the Iris, the flower will not be a whole, to produce one leading idea in which the others it may suggest are contained, but will be broken into parts, and its effectiveness diminished to that of a flower of the size of one of its parts.

Or the general appearance will be marred by the impression of roughness and harshness, causing to the eye a sensation analogous to that communicated to the hand by its passing over a rough uneven surface. This is exemplified in many flowers, even in the Lily, and still more in the ragged edge of some Pinks and Carnations; because in them the defect is in such close juxtaposition with the means of its cure - a curve in the outline of the petal; and this curve already exists at the base of the serrated point. It always gives an idea of harshness.

It is not, however, always that these defects can be expected, or wished, to be removed by cultivation. In the Gladiolus, Iris, Ixia, and others, they are of the essence of the form, and the flower would quite alter its character were they removed. The alteration, if effected, would very possibly be no improvement; and at least it would be a complete transformation of the original. When this is the case, the flower must be content to take a lower rank, with such as are incapable of the highest assemblage of excellences, but not the less esteemed for the qualities it does possess. Nor is it desirable that all should be of one class.

Moreover, in some of this class the primary outline which gives the leading impression of the flower lies within the irregular parts, as in the Tigridia; the slightly concave disc of which is sufficiently distinct, and the protruding flaps of the alternate longer petals overhang its edge, and sometimes fall down from it like the lappets of a lady's head-dress of the reign of Queen Anne. Owing to this, the flimsy substance of the outer portion of the longer petals is no fault.

Nor is unity altogether lost in any of these flowers, except in such as contain a primary division of the corolla into two or more like and equal parts, as the Iris does, and many smaller flowers, as the Veronica instanced above, in which the parts are circular, and therefore complete in themselves.

This quality, therefore, is most essential to the flower as a whole; and should accordingly be always more or less found under the general outline.

Next let us consider the effect of variety. This is even more essential to a pleasing form than unity is. It is, as it were, the substance, while unity is the form in which that substance should be presented; for without it, the ideas suggested can be at best but scanty; and it is by a succession of ideas that pleasurable emotions are excited; while at the same time variety, though ever so charming, if not included in one leading impression, will be desultory and unconnected; there will be a break in the current of thought, and the result will be harsh and disagreeable.