which have led up to it; and, finally, we admire the correlation of sweet secretion with gay colour or pleasant odour.

With regard to the colours of birds and butterflies the case is different, for here the element of conscious choice comes in. Let it be the case, as Hunter said it was, that the female requires to be courted; let it be the fact, as Darwin and Wallace affirm (and they have a host of naturalists at their back), that male birds assiduously display their plumage, perform strange antics, and pour forth their song in presence of the female; and grant that choice is exercised generation after generation, the repeated selection resulting in the great beauty of the males. Let us suppose that in the course of several thousands of generations we have one thousand variations of the right sort combined into one harmonious whole, like a thousand small pieces of mosaic artistically arranged into a pattern or picture. The process, indeed, is comparable to that by which some mosaic pictures of great excellence have been worked, with millions of tiny pieces, successive artists wearing out their lives upon them, each still leaving the picture for another to finish. The artists, however, leave us a picture at last, because there has been a design from the first; and each man could fit his work. on to that of his predecessor, because he had the same original sketch to work by. But the female bird has no prevision of the final result, no hand in putting a new piece to the mosaic (she only stamps it to remain when

variation" has introduced it), and yet the eventual forms of beauty, as, for instance, in the peacock's tail, seem to imply the action of mind somewhere. If the female bird could see the end from the beginning, and consciously work towards it, this would be quite as

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wonderful as the Creator designing the result, and working for it; and, on the other hand, as Mr Wallace remarks, successive generations of female birds choosing any little variety of colour that occurred among their suitors, would necessarily lead to a speckled or piebald and unstable result, not to the beautiful definite colours and markings we see.1 Admitting that the exquisite colours, patterns, and ornaments require the agency of the bird's mind for their evolution, can we suppose that the plumage and the mind together, and all the beauty in nature, have come about without the agency of a greater Mind? Mr Wallace's view is, that some law of necessary development of colour in certain parts of the body and in certain hues is first required; and then, perhaps, in the case of birds, the females might choose the successive improvements as they occurred; though, unless other variations were altogether prevented, it seems just as likely that they would mar the effect the law of development of colour was tending to proluce." There can be no objection to this "law" of levelopment—this cause working uniformly; and should chis cause be traced down to a deeper cause, it matters not (we have met the case before)—however deep the succession of cause underlying cause, we have on the surface marks of mind, and at the bottom mind itself, or else the pattern showing itself through all the sheets has no type underneath to impress it.

Perhaps even the want of beauty in some forms, and ts lavish scattering where man cannot see it, may admit of explanation. It must be admitted at once that beauty was not intended for man's admiration alone; for the shells and corals of the old Silurian sea were

1 Academy, March 1871.

elaborate and richly carved, the marine mollusca of today are rich in ornament, and the graceful patterns of the Diatomaceæ, which no graver's tool could imitate, are invisible except with the microscope. It is equally certain, however, that all beauty is not the result of sexual selection; Mr Darwin himself allowing that in the lower divisions of the animal kingdom sexual selection seems to have done nothing-could do nothing 1while here we find the gorgeous tints of the sea-anemone, the lustrous sheen of the sea-slug, and all the exquisite carving of sea-shells. Mr Wallace points out that even among insects it is only in butterflies that any difference in beauty occurs in the sexes; and that in caterpillars, which of course do not mate together, we have almost all the classes of coloration found in perfect insects -protective and conspicuous tints; spots, streaks, bands, and patterns; beautiful fleshy tubercles or tentacles; beautifully coloured hairs arranged in tufts, brushes, starry clusters or long pencils; horns on the head o tail, either single or double, pointed or clubbed, &c.

To these two facts, viz., that beauty is not all for man's sake, and is not all produced by sexual selection, let us add a third, which is, that beauty is not always useful, and therefore not always produced by Natural Selection working directly in any form, but is apparently correlated with what is useful. Mr Darwin says "The most probable view in regard to the splendid tints of many of the lowest animals seems to be that thei colours are the direct result either of the chemical nature or the minute structure of their tissues, independently of any benefit thus derived. Hardly any colour is fine than that of arterial blood; but there is no reason to 1 Descent of Man, ii. 396.

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suppose that the colour of the blood is in itself any advantage; and though it adds to the beauty of the maiden's cheek, no one will pretend that it has been acquired for this purpose. So again with many animals, especially the lower ones, the bile is richly coloured; thus the extreme beauty of the Eolidæ (naked sea-slugs) is chiefly due, as I am informed by Mr Hancock, to the biliary glands seen through the translucent integuments, this beauty being probably of no service to these animals. The tints of the decaying leaves in an American forest are described by every one as gorgeous; yet no one supposes that these tints are of the least advantage to the trees. Bearing in mind how many substances closely analogous to natural organic compounds have been recently formed by chemists, and which exhibit the most splendid colours, it would have been a strange fact if substances similarly coloured had not often originated, independently of any useful end being thus gained, in the complex laboratory of living organisms."1 Exactly so decaying leaves must have some colour-i.e., they must bear some relation to the vibrations of the ether, and therefore to the eyes which are attuned to certain sets of vibrations-their tints may be a necessity of their molecular condition at the moment; and so may be the tints of the flower which the insect selects to fertilise, and the colours of a bird's feathers which happen to please the female or happen to be always covered from view and so can please nobody. But then, as the chemist can introduce a new element changing the molecular state of a dye, and with it the colour, so this inevitable correlation in nature need not shut the door to all choice.

1 Descent of Man, ii. 323.

Next, let it be allowed to us that beauty is not a mere matter of fancy, but that its standard is immutable-as mathematical truth is immutable-so that it must bear the same appearance to all intelligences of a sufficiently high order. It is no argument against this that men's tastes differ or that savages distort the features and call the distortion beauty; for the same savages prefer hideous howling to the grandeur of an oratorio, and would probably confound all ellipses with circles. Grant that true beauty is something independent of caprice and fashion, and some light is thrown on the question we are discussing. First we get some explanation of the "remarkable circumstance" noted by Mr Spencer, "that these [sexual] characteristics which have originated by furthering the production of the best offspring, while they are naturally those which render the organisms possessing them attractive to one another, directly or indirectly, should also be those which are so generally attractive to us-those without which the fields and woods would lose half their charm.”1 Mr Darwin says, "The mental powers of birds, if reason be excluded, do not fundamentally differ from ours;""birds have fine powers of discrimination, and in some few instances it can be shown that they have a taste for the beautiful;"-" assuredly the same colours and the same sounds are admired by us and by many of the lower animals ;”—_" there is no abstract improbability in the Lepidoptera, which probably stand nearly or quite as high in the scale as these insects [ants and beetles], having sufficient mental capacity to admire bright colours." This seems reasonable: as birds and butterflies and all creatures with eyes related to the external

1 Principles of Biology, ii. 253.