Kitabı oku: «The Evolutionist at Large», sayfa 8

XX.
BLACKCOCK

Just at the present moment the poor black grouse are generally having a hot time of it. After their quiet spring and summer they suddenly find their heath-clad wastes invaded by a strange epidemic of men, dogs, and hideous shooting implements; and being as yet but young and inexperienced, they are falling victims by the thousand to their youthful habit of clinging closely for protection to the treacherous reed-beds. A little later in the season, those of them that survive will have learned more wary ways: they will pack among the juniper thickets, and become as cautious on the approach of perfidious man as their cunning cousins, the red grouse of the Scottish moors. But so far youthful innocence prevails; no sentinels as yet are set to watch for the distant gleam of metal, and no foreshadowing of man's evil intent disturbs their minds as they feed in fancied security upon the dry seeds of the marsh plants in their favourite sedges.

The great families of the pheasants and partridges, in which the blackcock must be included, may be roughly divided into two main divisions so far as regards their appearance and general habits. The first class consists of splendidly coloured and conspicuous birds, such as the peacock, the golden pheasant, and the tragopan; and these are, almost without exception, originally jungle-birds of tropical or sub-tropical lands, though a few of them have been acclimatised or domesticated in temperate countries. They live in regions where they have few natural enemies, and where they are little exposed to the attacks of man. Most of them feed more or less upon fruits and bright-coloured food-stuffs, and they are probably every one of them polygamous in their habits. Thus we can hardly doubt that the male birds, which alone possess the brilliant plumage of their kind, owe their beauty to the selective preference of their mates; and that the taste thus displayed has been aroused by their relation to their specially gay and bright natural surroundings. The most lovely species of pheasants are found among the forests of the Himalayas and the Malay Archipelago, with their gorgeous fruits and flowers and their exquisite insects. Even in England our naturalised Oriental pheasants still delight in feeding upon blackberries, sloes, haws, and the pretty fruit of the honeysuckle and the holly; while our dingier partridges and grouse subsist rather upon heather, grain, and small seeds. Since there must always be originally nearly as many cocks as hens in each brood, it will follow that only the handsomest or most attractive in the polygamous species will succeed in attracting to them a harem; and as beauty and strength usually go hand in hand, they will also be the conquerors in those battles which are universal with all polygamists in the animal world. Thus we account for the striking and conspicuous difference between the peacock and the peahen, or between the two sexes in the pheasant, the turkey, and the domestic fowl.

On the other hand, the second class consists of those birds which are exposed to the hostility of many wild animals, and more especially of man. These kinds, typified by the red grouse, partridges, quails, and guinea-fowls, are generally dingy in hue, with a tendency to pepper-and-salt in their plumage; and they usually display very little difference between the sexes, both cocks and hens being coloured and feathered much alike. In short, they are protectively designed, while the first class are attractive. Their plumage resembles as nearly as possible the ground on which they sit or the covert in which they skulk. They are thus enabled to escape the notice of their natural enemies, the birds of prey, from whose ravages they suffer far more in a state of nature than from any other cause. We may take the ptarmigans as the most typical example of this class of birds; for in summer their zigzagged black-and-brown attire harmonises admirably with the patches of faded heath and soil upon the mountain-side, as every sportsman well knows; while in the winter their pure white plumage can scarcely be distinguished from the snow in which they lie huddled and crouching during the colder months. Even in the brilliant species, Mr. Darwin and Mr. Wallace have pointed out that the ornamental colours and crest are never handed down to female descendants when the habits of nesting are such that the mothers would be exposed to danger by their conspicuousness during incubation. Speaking broadly, only those female birds which build in hollow trees or make covered nests have bright hues at all equal to those of the males. A female bird nesting in the open would be cut off if it showed any tendency to reproduce the brilliant colouring of its male relations.

Now the blackcock occupies to some extent an intermediate position between these two types of pheasant life, though it inclines on the whole to that first described. It is a polygamous bird, and it differs most conspicuously in plumage from its consort, the grey-hen, as may be seen from the very names by which they are each familiarly known. Yet, though the blackcock is handsome enough and shows evident marks of selective preference on the part of his ancestral hens, this preference has not exerted itself largely in the direction of bright colour, and that for two reasons. In the first place the blackcock does not feed upon brilliant foodstuffs, but upon small bog-berries, hard seeds, and young shoots of heather, and it is probable that an æsthetic taste for pure and dazzling hues is almost confined to those creatures which, like butterflies, hummingbirds, and parrots, seek their livelihood amongst beautiful fruits or flowers. In the second place, red, yellow, or orange ornaments would render the blackcock too conspicuous a mark for the hawk, the falcon, or the weapons of man; for we must remember that only those blackcocks survive from year to year and hand down their peculiarities to descendants which succeed in evading the talons of birds of prey or the small-shot of sportsmen. Feeding as they do on the open, they are not protected, like jungle-birds, by the shade of trees. Thus any bird which showed any marked tendency to develop brighter or more conspicuous plumage would almost infallibly fall a victim to one or other of his many foes; and however much his beauty might possibly charm his mates (supposing them for the moment to possess a taste for colour), he would have no chance of transmitting it to a future generation. Accordingly, the decoration of the blackcock is confined to glossy plumage and a few ornamental tail-feathers. The grey-hen herself still retains the dull and imitative colouring of the grouse race generally; and as for the cocks, even if a fair percentage of them is annually cut off through their comparative conspicuousness as marks, their loss is less felt than it would be in a monogamous community. Every spring the blackcock hold a sort of assembly or court of love, at which the pairing for the year takes place. The cocks resort to certain open and recognised spots, and there invite the grey-hens by their calls, a little duelling going on meanwhile. During these meetings they show off their beauty with great emulation, after the fashion with which we are all familiar in the case of the peacock; and when they have gained the approbation of their mates and maimed or driven away their rivals, they retire with their respective families. Unfortunately, like most polygamists, they make bad fathers, leaving the care of their young almost entirely to the hens. According to the veracious account of Artemus Ward, the great Brigham Young himself pathetically descanted upon the difficulty of extending his parental affections to 131 children. The imperious blackcock seems to labour under the same sentimental disadvantage.

XXI.
BINDWEED

Not the least beautiful among our native wild flowers are many of those which grow, too often unheeded, along the wayside of every country road. The hedge-bordered highway on which I am walking to-day, to take my letters to the village post, is bordered on either side with such a profusion of colour as one may never see equalled during many years' experience of tropical or sub-tropical lands. Jamaica and Ceylon could produce nothing so brilliant as this tangled mass of gorse, and thistle, and St. John's-wort, and centaury, intermingled with the lithe and whitening sprays of half-opened clematis. And here, on the very edge of the road, half-smothered in its grey dust, I have picked a pretty little convolvulus blossom, with a fly buried head-foremost in its pink bell; and I am carrying them both along with me as I go, for contemplation and study. For this little flower, the lesser bindweed, is rich in hints as to the strange ways in which Nature decks herself with so much waste loveliness, whose meaning can only be fully read by the eyes of man, the latest comer among her children. The old school of thinkers imagined that beauty was given to flowers and insects for the sake of man alone: it would not, perhaps, be too much to say that, if the new school be right, the beauty is not in the flowers and insects themselves at all, but is read into them by the fancy of the human race. To the butterfly the world is a little beautiful; to the farm-labourer it is only a trifle more beautiful: but to the cultivated man or the artist it is lovely in every cloud and shadow, in every tiny blossom and passing bird.

The outer face of the bindweed, the exterior of the cup, so to speak, is prettily marked with five dark russet-red bands, between which the remainder of the corolla is a pale pinky-white in hue. Nothing could be simpler and prettier than this alternation of dark and light belts; but how is it produced? Merely thus. The convolvulus blossom in the bud is twisted or contorted round and round, part of the cup being folded inside, while the five joints of the corolla are folded outside, much after the fashion of an umbrella when rolled up. And just as the bits of the umbrella which are exposed when it is folded become faded in colour, so the bits of the bindweed blossom which are outermost in the bud become more deeply oxidised than the other parts, and acquire a russet-red hue. The belted appearance which thus results is really as accidental, if I may use that unphilosophical expression, as the belted appearance of the old umbrella, or the wrinkles caused by the waves on the sea-sands. The flower happened to be folded so, and got coloured, or discoloured, accordingly. But when a man comes to look at it, he recognises in the alternation of colours and the symmetrical arrangement one of those elements of beauty with which he is familiar in the handicraft of his own kind. He reads an intention into this result of natural causes, and personifies Nature as though she worked with an æsthetic design in view, just as a decorative artist works when he similarly alternates colours or arranges symmetrical and radial figures on a cup or other piece of human pottery. The beauty is not in the flower itself; it is in the eye which sees and the brain which recognises the intellectual order and perfection of the work.

I turn the bindweed blossom mouth upward, and there I see that these russet marks, though paler on the inner surface, still show faintly through the pinky-white corolla. This produces an effect not unlike that of a delicate shell cameo, with its dainty gradations of semi-transparent white and interfusing pink. But the inner effect can be no more designed with an eye to beauty than the outer one was; and the very terms in which I think of it clearly show that my sense of its loveliness is largely derived from comparison with human handicraft. A farmer would see in the convolvulus nothing but a useless weed; a cultivated eye sees in it just as much as its nature permits it to see. I look closer, and observe that there are also thin lines running from the circumference to the centre, midway between the dark belts. These lines, which add greatly to the beauty of the flower, by marking it out into zones, are also due to the folding in the bud; they are the inner angles of the folds, just as the dark belts are the overlapping edges of the outer angles. But, in addition to the minor beauty of these little details, there is the general beauty of the cup as a whole, which also calls for explanation. Its shape is as graceful as that of any Greek or Etruscan vase, as swelling and as simply beautiful as any beaker. Can I account for these peculiarities on mere natural grounds as well as for the others? I somehow fancy I can.

The bindweed is descended from some earlier ancestors which had five separate petals, instead of a single fused and circular cup. But in the convolvulus family, as in many others, these five petals have joined into a continuous rim or bowl, and the marks on the blossom where it was folded in the bud still answer to the five petals. In many plants you can see the pointed edges of the former distinct flower-rays as five projections, though their lower parts have coalesced into a bell-shaped or tubular blossom, as in the common harebell. How this comes to pass we can easily understand if we watch an unopened fuchsia; for there the four bright-coloured sepals remain joined together till the bud is ready to open, and then split along a line marked out from the very first. In the plastic bud condition it is very easy for parts usually separate so to grow out in union with one another. I do not mean that separate pieces actually grow together, but that pieces which usually grow distinct sometimes grow united from the very first. Now, four or five petals, radially arranged, in themselves produce that kind of symmetry which man, with his intellectual love for order and definite patterns, always finds beautiful. But the symmetry in the flower simply results from the fact that a single whorl of leaves has grown into this particular shape, while the outer and inner whorls have grown into other shapes; and every such whorl always and necessarily presents us with an example of the kind of symmetry which we so much admire. Again, when the petals forming a whorl coalesce, they must, of course, produce a more or less regular circle. If the points of the petals remain as projections, then we get a circle with vandyked edges, as in the lily of the valley; if they do not project, then we get a simple circular rim, as in the bindweed. All the lovely shapes of bell-blossoms are simply due to the natural coalescence of four, five, or six petals; and this coalescence is again due to an increased certainty of fertilisation secured for the plant by the better adaptation to insect visits. Similarly, we know that the colours of the corolla have been acquired as a means of rendering the flower conspicuous to the eyes of bees or butterflies; and the hues which so prove attractive to insects are of the same sort which arouse pleasurable stimulation in our own nerves. Thus the whole loveliness of flowers is in the last resort dependent upon all kinds of accidental causes – causes, that is to say, into which the deliberate design of the production of beautiful effects did not enter as a distinct factor. Those parts of nature which are of such a sort as to arouse in us certain feelings we call beautiful; and those parts which are of such a sort as to arouse in us the opposite feelings we call ugly. But the beauty and the ugliness are not parts of the things; they are merely human modes of regarding some among their attributes. Wherever in nature we find pure colour, symmetrical form, and intricate variety of pattern, we imagine to ourselves that nature designs the object to be beautiful. When we trace these peculiarities to their origin, however, we find that each of them owes its occurrence to some special fact in the history of the object; and we are forced to conclude that the notion of intentional design has been read into it by human analogies. All nature is beautiful, and most beautiful for those in whom the sense of beauty is most highly developed; but it is not beautiful at all except to those whose own eyes and emotions are fitted to perceive its beauty.

XXII.
ON CORNISH CLIFFS

I am lying on my back in the sunshine, close to the edge of a great broken precipice, beside a clambering Cornish fishing village. In front of me is the sea, bluer than I have seen it since last I lay in like fashion a few months ago on the schistose slopes of the Maurettes at Hyères, and looked away across the plain to the unrippled Mediterranean and the Stœchades of the old Phocæan merchant-men. On either hand rise dark cliffs of hornblende and serpentine, weathered above by wind and rain, and smoothed below by the ceaseless dashing of the winter waves. Up to the limit of the breakers the hard rock is polished like Egyptian syenite; but beyond that point it is fissured by disintegration and richly covered with a dappled coat of grey and yellow lichen. The slow action of the water, always beating against the solid wall of crystalline rock, has eaten out a thousand such little bays all along this coast, each bounded by long headlands, whose points have been worn into fantastic pinnacles, or severed from the main mass as precipitous islets, the favourite resting-place of gulls and cormorants. No grander coast scenery can be found anywhere in the southern half of Great Britain.

Yet when I turn inland I see that all this beauty has been produced by the mere interaction of the sea and the barren moors of the interior. Nothing could be flatter or more desolate than the country whose seaward escarpment gives rise to these romantic coves and pyramidal rocky islets. It stretches away for miles in a level upland waste, only redeemed from complete barrenness by the low straggling bushes of the dwarf furze, whose golden blossom is now interspersed with purple patches of ling or the paler pink flowers of the Cornish heath. Here, then, I can see beauty in nature actually beginning to be. I can trace the origin of all these little bays from small rills which have worn themselves gorge-like valleys through the hard igneous rock, or else from fissures finally giving rise to sea-caves, like the one into which I rowed this morning for my early swim. The waves penetrate for a couple of hundred yards into the bowels of the rock, hemmed in by walls and roof of dark serpentine, with its interlacing veins of green and red bearing witness still to its once molten condition; and at length in most cases they produce a blow-hole at the top, communicating with the open air above, either because the fissure there crops up to the surface, or else through the agency of percolation. At last, the roof falls in; the boulders are carried away by the waves; and we get a long and narrow cove, still bounded on either side by tall cliffs, whose summits the air and rainfall slowly wear away into jagged and exquisite shapes. Yet in all this we see nothing but the natural play of cause and effect; we attribute the beauty of the scene merely to the accidental result of inevitable laws; we feel no necessity for calling in the aid of any underlying æsthetic intention on the part of the sea, or the rock, or the creeping lichen, in order to account for the loveliness which we find in the finished picture. The winds and the waves carved the coast into these varied shapes by force of blind currents working on hidden veins of harder or softer crystal: and we happen to find the result beautiful, just as we happen to find the inland level dull and ugly. The endless variety of the one charms us, while the unbroken monotony of the other wearies and repels us.

Here on the cliff I pick up a pretty fern and a blossoming head of the autumn squill – though so sweet a flower deserves a better name. This fern, too, is lovely in its way, with its branching leaflets and its rich glossy-green hue. Yet it owes its shape just as truly to the balance of external and internal forces acting upon it as does the Cornish coast-line. How comes it then that in the one case we instinctively regard the beauty as accidental, while in the other we set it down to a deliberate æsthetic intent? I think because, in the first case, we can actually see the forces at work, while in the second they are so minute and so gradual in their action as to escape the notice of all but trained observers. This fern grows in the shape that I see, because its ancestors have been slowly moulded into such a form by the whole group of circumstances directly or indirectly affecting them in all their past life; and the germ of the complex form thus produced was impressed by the parent plant upon the spore from which this individual fern took its birth. Over yonder I see a great dock-leaf; it grows tall and rank above all other plants, and is able to spread itself boldly to the light on every side. It has abundance of sunshine as a motive-power of growth, and abundance of air from which to extract the carbon that it needs. Hence it and all its ancestors have spread their leaves equally on every side, and formed large flat undivided blades. Leaves such as these are common enough; but nobody thinks of calling them pretty. Their want of minute subdivision, their monotonous outline, their dull surface, all make them ugly in our eyes, just as the flatness of the Cornish plain makes it also ugly to us. Where symmetry is slightly marked and variety wanting, as in the cabbage leaf, the mullein, and the burdock, we see little or nothing to admire. On the other hand, ferns generally grow in hedge-rows or thickets, where sunlight is much interrupted by other plants, and where air is scanty, most of its carbon being extracted by neighbouring plants which leave but little for one another's needs. Hence you may notice that most plants growing under such circumstances have leaves minutely sub-divided, so as to catch such stray gleams of sunlight and such floating particles of carbonic acid as happen to pass their way. Look into the next tangled and overgrown hedge-row which you happen to pass, and you will see that almost all its leaves are of this character; and when they are otherwise the anomaly usually admits of an easy explanation. Of course the shapes of plants are mostly due to their normal and usual circumstances, and are comparatively little influenced by the accidental surroundings of individuals; and so, when a fern of such a sort happens to grow like this one on the open, it still retains the form impressed upon it by the life of its ancestors. Now, it is the striking combination of symmetry and variety in the fern, together with vivid green colouring, which makes us admire it so much. Not only is the frond as a whole symmetrical, but each frondlet and each division of the frondlet is separately symmetrical as well. This delicate minuteness of workmanship, as we call it, reminds us of similar human products – of fine lace, of delicate tracery, of skilful filagree or engraving. Almost all the green leaves which we admire are noticeable, more or less, for the same effects, as in the case of maple, parsley, horse-chestnut, and vine. It is true, mere glossy greenness may, and often does, make up for the want of variety, as we see in the arum, holly, laurel, and hart's-tongue fern; but the leaves which we admire most of all are those which, like maidenhair, are both exquisitely green and delicately designed in shape. So that, in the last resort, the beauty of leaves, like the beauty of coast scenery, is really due to the constant interaction of a vast number of natural laws, not to any distinct aesthetic intention on the part of Nature.

On the other hand, the pretty pink squill reminds me that semi-conscious aesthetic design in animals has something to do with the production of beauty in nature – at least, in a few cases. Just as a flower garden has been intentionally produced by man, so flowers have been unconsciously produced by insects. As a rule, all bright red, blue, or orange in nature (except in the rare case of gems) is due to animal selection, either of flowers, fruits, or mates. Thus we may say that beauty in the inorganic world is always accidental; but in the organic world it is sometimes accidental and sometimes designed. A waterfall is a mere result of geological and geographical causes, but a bluebell or a butterfly is partly the result of a more or less deliberate æsthetic choice.