the functions which each part fulfils; and there is surely some ground for concluding that He who planned and made them all superadded those qualities, and instituted a harmony between the sensate and the insensate, for the gratification of animal tastes. Not only so, we think there is good ground for affirming that not a few vegetable forms were meant to gratify the æsthetic feelings of man. We cannot declare with certainty that the forms assumed by the flower, by its calyx and corolla, are in every case necessary to the functions of the plant. We will not affirm that the beautifully rounded form of the peach, the delicacy of bloom on the surface, and the deliciousness of its flavour, are required in order to the production of the kernel and its hard protecting shell. We have no reason to think that the brilliant scales on the wings of the butterfly are necessary to its flight, for the insect, (as any one may observe) can fly after they are mostly all rubbed off, and some Lepidoptera have few or no scales at all; and just as little ground have we for affirming that the plant could not fulfil its functions even though the flower had not been so ornamented.

Man has æsthetic tastes implanted in his nature; these are gratified to the full by the lovely forms presented in the vegetable kingdom, and we are convinced that all this was arranged by Him who conferred on man his love of the beautiful, and supplied the objects by which that love is gratified. And here we have to express our regret that philosophers have not been able to agree upon a theory of the beautiful. If there had been any acknowledged doctrine on this subject,

*Some insist that there is not only the beautiful in plants, (and in animals as well,) but also the grotesque. Granted, but surely we have here a further example of final cause in the relation between the grotesque in the plant and the sense of the ludicrous

in man.

there would have been little difficulty in shewing that plants are fashioned in accordance with a very high style of beauty. In particular, we are as yet without any generally received principles in regard to what constitutes beauty of form. In such circumstances we can appeal to no admitted rules, but we can appeal to our own feelings, which declare that the plant, in its general form, and in its corolla, exhibits perfect models of beauty. Here we have an all-sufficient final cause superadded to all the other final causes, bearing more directly upon the economy of the plant, and coming in at the parts, such as the flower and fruit, where these others, to our eyes, might seem to fail.

7

CHAPTER III.

THE COLOURS OF PLANTS.

SECT. I.-THE RELATIONS OF FORM AND COLOUR IN THE FLOWER.

It is a very common impression that there is no rule, no law, for the distribution of colours in the vegetable kingdom. We are convinced that this is a fundamental mistake. Little, it is true, has been done to establish scientific principles as to the colours of plants. Still, there is reason to believe that system prevails here as in every other department of nature. Laws in regard to the form, structure, number, and position of organs, are familiar to every botanist; and it is surely not unreasonable to expect that order may also be found in the placing of colours. One of us has been able to furnish a contribution to this branch of inquiry, by discovering evidence of a very curious relation between the form and colour in the corolla in plants.†

In order that this may be understood, it will be necessary at this place to explain certain technical terms used

*We are great admirers of Mr. Ruskin's intuitional power, but the following statements in his Lamps of Architecture are too unguarded:-"The natural colour of objects never follows form, but is arranged on a different principle;" and again, "Colour is simplified where form is rich, and vice versa;" "In nature," he further says, the "boundaries of forms are elegant and precise; those of colours, though subject to symmetry of a rude kind, are yet irregular--in blotches."

+ See Dr. Dickie's Papers in Sectional Reports of Proceedings of British Association, 1954; and Annals of Natural History, Dec. 1854.

by botanists. The term regular is applied to every calyx or corolla in which each sepal or petal is of equal size and of similar form; in other words, in which all the divisions (whether they are free or adhere to each other by their edges*) are equally and uniformly developed. Every flower in which there is unequal or irregular development of sepals and of petals, is called irregular. It is to the very great difference in these respects that we owe the variety of aspect in the flowers of different species. As examples, the following familiar plants may be adduced;-the pansy has an irregular flower, that of wall-flower is regular; a primrose has a regular flower; a snapdragon presents an example of irregu larity.

The following conclusions appear generally to hold good as to the relation of form and of colour in the flower.

1. In regular corollas the colour is uniformly distributed whatever be the number of colours present.—That is to say, the pieces of the corolla being all alike in size and form, have each an equal proportion of colour. The common primrose is an example where there is only one colour. In the Chinese primrose the same holds where two colours (the one the complement of the other) are present, the eye or centre being yellow, and the margin purple; these two colours in this regular flower are uniformly diffused, that is, each piece has an equal proportion of yellow and of purple respectively. In Myosotis, Anagallis, Erica, Gentiana, Pyrola, &c., we have uniform corolla with uniform distinction of colour. All Corolliflora Exogens with regular flowers are examples; the same is true of certain Thalamifloræ, as Papaveraceæ, Cruciferæ,

It may be necessary to explain that the terms free or adherent, refer to the condition of the mature flower, and not to the inode of development.

&c.; Calycifloral* Exogens with regular flowers, as Rosaceæ, Cactaceæ, &c., illustrate the same principle.

2. Irregularity of corolla is associated with irregular distribution of colour, whether one or more colours are present. In irregular flowers where the number five prevails, the odd piece is most varied in form, size, and colour. When only one colour is present, it is usually more intense in the odd lobe of the corolla. When there are two colours, one of them is generally confined to the odd piece. Sometimes when only one colour is present, and of uniform intensity in all the pieces, the odd segment has spots or streaks of white. A few familiar instances may suffice.

Common Laburnum,

Trifolium pratense, (common red-clover,). . . . Kennedia monophylla,.

Swainsonia purpurea, .

......

Ajuga reptans, (common

bugle,).....

Four petals yellow; fifth, yellow, with purple veins.

Odd piece distinguished from the others by its darker purple veins.

Four petals yellow; fifth, yellow eye and purple margin.

Four petals yellow; fifth, white eye on purple ground.

Four divisions purple; fifth, has yellow spot on inner surface.

Thymus Serpyllum, (wild) Corolla generally red purple; two pale

thyme,)

Galeopsis Tetrahit,.

piece has purple spots on yellow ground.

Euphrasia officinalis, (com- Corolla purple generally; odd piece has mon eyebright,)

.......

yellow spot.

In those well-known annuals, Collinsia and Schizanthus, the prevailing colour is purple; the primary, yellow, appears in the odd lobe.

*Thalamiflora comprehends plants in which there is no adhesion between the whorls of the flower. Calyciflora comprehends those in which there is such adhesion. In Corolliflora the petals are united by their edges forming a tubular flower, to the inside of which the stamens partially adhere.