or prairies occur nowhere in nature, except in places where the liability to destructive fires over wide areas together crushes out forest trees, or else where goats, bison, deer, and other large herbivores browse them ceaselessly down in the stage of seedlings. Competition for sunlight is thus even keener perhaps than competition for foodstuffs. Alike on trees, shrubs, and herbs accordingly the arrangement of the leaves is always exactly calculated so as to allow the largest possible horizontal surface, and the greatest exposure of the blade to the open sunshine. In trees this arrangement can often be very well observed, all the leaves being placed at the extremities of the branches, and forming a great dome-shaped or umbrella-shaped mass, every part of which stands an even chance of catching its fair share of carbonic acid and solar energy.

The shapes of the leaves themselves are also largely due to the same cause, every leaf being so designed in form and outline as to interfere as little as possible with the other leaves on the same stem, as regards supply both of light and of carbonaceous foodstuffs. It is only in rare cases, like that of the water-lily, that perfectly round leaves occur, because the conditions are seldom equal all round, and the incidence of light and the supply of carbon are seldom unlimited. But wherever leaves rise free and solitary into the air, without mutual interference, they are always circular, as may be well seen in the common nasturtium and the English pennywort. On the other hand, among dense hedgerows and thickets, where the silent, invisible struggle for life is very fierce indeed, and where sunlight and carbonic acid are intercepted by a thousand competing mouths and arins, the prevailing types of leaf are extremely cut up and minutely subdivided into small lace-like fragments. The plant in such cases can't afford material to fill up the interstices between the veins and ribs which determine its underlying architectural structure. Often indeed species which grow under these hard conditions produce leaves which are, as it were, but skeleton representatives of their large and well filled-out compeers in the open meadows.

It is only by bearing vividly in mind this ceaseless and noiseless struggle between plants for their gaseous food and the sunshine which enables them to digest it,

that we can ever fully understand the varying forms and habits of the vegetable kingdom. To most people, no doubt, it sounds like pure metaphor to talk of an internecine struggle between rooted beings which cannot budge one inch from their places, nor fight with horns, hoofs, or teeth, nor devour one another bodily, nor tread one another down with ruthless footsteps. But that is only because we habitually forget that competition is just as really a struggle for life as open warfare. The men who try against one another for a clerkship in the City, or a post in a gang of builder's workmen, are just as surely taking away bread and butter out of their fellows' mouths for their own advantage, as if they fought for it openly with fists or six-shooters. The white man who encloses the hunting grounds of the Indian, and plants them with corn, is just as surely dooming that Indian to death as if he scalped or tomahawked him. And so too with the unconscious warfare of plants. The daisy or the plantain that spreads its rosette of leaves flat against the ground is just as truly monopolizing a definite space of land as the noble owner of a Highland deer forest. No blade of grass can spring beneath the shadow of those tightly pressed little mats of foliage; no fragment of carbon, no ray of sunshine can ever penetrate below that close fence of living greenstuff.

Plants, in fact, compete with one another all round for everything they stand in need of. They compete for their food -carbonic acid. They compete for their energy-their fair share of sunlight. They compete for water, and their foothold in the soil. They compete for the favors of the insects that fertilize their flowers. They compete for the good services of the birds or mammals that disseminate their seeds in proper spots for germination. And how real this competition is we can see in a moment, if we think of the difficulties of human cultivation. There, weeds are always battling manfully with our crops or our flowers for mastery over the field or garden. We are obliged to root up with ceaseless toil these intrusive competitors, if we wish to enjoy the kindly fruits of the earth in due season. When we leave a garden to itself for a few short years, we realize at once what effect the competition of hardy natives has upon our carefully tended and unstable exotics. a very brief time the dahlias and phloxes

In

and lilies have all disappeared, and in their place the coarse-growing docks and nettles and thistles have raised their heads

aloft to monopolize air and space and sun

shine.

Exactly the same struggle is always taking place in the fields and woods and moors around us, and especially in the spots made over to pure nature. There, the greenwood tree raises its huge umbrella of foliage to the skies, and allows hardly a ray of sunlight to struggle through to the low woodland vegetation of orchid or wintergreen underneath. Where the Where the soil is not deep enough for trees to root securely, bushes and heathers overgrow the ground, and compete with their bellshaped blossoms for the coveted favor of bees and butterflies. And in open glades, where for some reason or other the forest fails, tall grasses and other aspiring herbs run up apace toward the free air of heaven. Elsewhere, creepers struggle up to the sun over the stems and branches of stronger bushes or trees, which they often choke and starve by monopolizing at last all the available carbon and sunlight. And so throughout; the struggle for life goes on just as ceaselessly and truly among these unconscious combatants as among the lions

and tigers of the tropical jungle, or among the human serfs of the overstocked market.

An ounce of example, they say, is worth a pound of precept. So a single concrete case of a fierce vegetable campaign now actually in progress over all Northern Europe may help to make my meaning a trifle clearer. Till very lately the forests of the north were largely com. posed in places of the light and airy silver birches. But with the gradual amelioration of the climate of our continent, which has been going on for several centuries, the beech, a more southern type of tree, has begun to spread slowly though surely northward. Now, beeches are greedy trees, of very dense and compact foliage; nothing else can grow beneath their thick shade, where once they have gained a foothold; and the seedlings of the silver birch stand no chance at all in the struggle for life against the serried leaves of their formidable rivals. The beech literally eats them out of house and home; and the consequence is that the thick and ruthless southern tree is at this very moment gradually superseding over vast tracts of country its more graceful and beautiful, but far less voracious competitor. Cornhill Magazine.

THAT sense of beauty to which the gorgeous plumage of the male birds in many species is an obvious and direct appeal, is by no means limited to the knowledge so naively shown by resplendent husbands and adoring wives, that fine feathers make fine birds. So common and varied is the pleasure derived from this sense, that in many kinds it extends to the conscious search for and appliance of beautiful objects in the decoration of nests, of pleasure-houses, and the enrichment of collections. This taste for ornament is by no means limited to birds kept in captivity, in which they often learn tricks and habits foreign to their nature from ennui and idleIn the freedom of English woods or Papuan jungles, they show the keenest pleasure in the strange or beautiful shapes and colors of flowers, of feathers, of fruits, of gay shells and insects, of woven fabrics, of metal, glass, and gems; and similar tastes shown in captivity are often but the

ness.

survival and maimed reproduction of their natural love for surrounding themselves with what pleases the eye. It appears in species where it might be least expected, and is developed to a point at which it becomes an artistic passion identical in motive and the means taken to gratify it, with the same taste and its expression by civilized man. It is not without reason that the Papuan, who lives naked under a tree, calls the gardener-bird" the master," which can build not only a nest, but a lovely pleasure-house besides, and adorns this with a hundred beautiful objects to satisfy æsthetic wants which the savage is not yet developed enough to feel or understand.

But these tastes appear in birds which are quite low in the scale of mental development, even among the hawks, which are among the least keen-witted of the birds. The kite, for instance, has a great liking for pretty things, or what it con

siders such. In two of the rare instances in which the kite's nest has been recently found in this country, the cock bird had carried home a long, trailing spray of woodbine in flower, and left it by the side of its mate. When kites were common in England, their habit of carrying off to their nests any strange objects which took their fancy was well known. "The white sheet bleaching on the hedge" has as great attractions for them as it had for Autolycus. Shakespeare makes the peddler refer to this habit. My traffic is sheets," he says; when the kite builds, look to lesser linen." But the bird, though as much a snapper-up of unconsidered trifles" as Autolycus himself, is only a fine-art and bric-à-brac collector in its way, and is perhaps not more unscrupulous in annexing the specimens that take its fancy. In a kite's nest found not long ago in this country, the collection" was enriched by pieces of newspaper and leaves of Bradshaw's Railway Guide !"-and on the few estates in England where these birds are still protected, the keepers are said to be quite aware of their mania for collecting linen when laid out to dry, and carrying off socks and bright cotton handkerchiefs to the nest.

The sense of beauty naturally appears, in the rudest and most elementary form, in such uncouth robbers as the kites. In the far cleverer crows, ravens, magpies, and jays, it is a marked and hereditary passion. From the Jackdaw of Rheims to the old raven at the Tower of London, who amassed a unique and valuable collection at the bottom of one of the venerable cannon inside the Barbican, there can hardly have existed a tame member of the tribe which has not at times asserted its own right to a share in the enjoyment of what we remember to have seen described in the pompous advertisement of a modern art furnisher, as "those products of the minor arts which contribute to the dignity and refinement of domestic life." They have a wide and catholic sense of feeling for what may contribute to their happiness in this way, and do not always distinguish between what is beautiful and what is merely curious. At the same time, they do often distinguish and keep apart what they collect or steal for food, and their art collections, which are hidden separately, and far more carefully concealed. The writer has seen this in the case of tame

jays and jackdaws, and has known it practised by a raven and a magpie. The latter always hid the crusts, and especially the small squares of toast made ready for soup, which he stole or had given him in the kitchen, between the layers of household linen in the drying-room of a large house in Northumberland. But his collections" were buried in the straw in a disused outhouse. The loss of several small cups and saucers out of a bright-colored set belonging to the children led to the discovery of this hoard, as the bird was seen to enter the shed, and was there found pulling away the straw which covered the china.

So far, we have traced the development of this sense of beauty from the kites, which merely pick up and carry to their nests what they consider to be pretty and interesting, to the crow tribe, which have a separate hiding-place for keeping and enjoying their treasures. The conscious search for and application of ornament to the decoration of the fabric of the nest, even at the risk of its danger and discovery through the gratification of their feeling for beauty, is a further and most remarkable evidence of the pleasure which they derive from that sense; for one of the strongest impulses of the nesting bird is to subordinate the color and texture of the outside of the nest to the tint of its natural surroundings, and none but a strong and tempting bias to the indulgence of a contrary instinct could compete with their natural solicitude for the safety of their young. Yet two undoubted instances of the addition of ornament by English birds to the outside of a nest have come under the writer's notice, where its use clearly entailed some danger from the enemy. The first was the nest of a chiff-chaff, found in a plantation near Rosamond's Bower, on the Isis, near Godstow. It was a domed nest of the usual kind, made of dry, colorless grass, with an entrance in the side. But on the outside, and round the entrance to the chamber, were stuck several of the brilliant blue feathers of the kingfisher. The position of these bright patches of color on the outside of the nest is strong evidence that beauty, not utility, was the object of their insertion. The other case was the nest of a goldfinch, which was built on a high branch of a sycamore, near the window of a house at Sidmouth, in Devonshire. When the

fabric of the nest was completed, the birds, or, rather, one bird, for the other was constantly employed in building, brought long pieces of the blue forget-menot from the next garden, and so adjusted the sprays that the flowers hung all round the top of the nest. The sacrifice of safety to beauty did not cause any risk from below, as the nest was at a considerable height from the ground. Unfortunately, it attracted the notice of a jackdaw or crow passing overhead; and the black robber plundered the nest of the eggs on which the bird had been sitting for some days. It may be noticed that in both these cases, in each of which there was a large choice of flowers or feathers for the feathers for the interior of the chiffchaff's nest were brought from a farmyard near the irresistible color was light-blue. This decorative instinct finds its final and complete expression in the bower-birds, and the still more interesting gardener-bird of New Guinea, both of which construct a palace of art" for the reception of their treasures and the full and free enjoyment of their sense of the beautiful. These "bowers" are in no sense nests; they are simply "art-galleries,' constructed for the better enjoyment of the honey-moon, and are altogether apart from the latter cares of the nest or nursery. "The best of all are the galleries of the "gardenerbird" recently found by Count Rosenberg in New Guinea. "It was a piece of workmanship more lovely than the ingenuity of animal has been known to construct,' any says the discoverer. "It was a temple in miniature, in the midst of a meadow studded with flowers." The bird, which is not much larger than a thrush, chooses a

level place round some shrub which has a straight stem about the thickness of a walking-stick. To this central pilaster it fastens the stems of a kind of orchid, and draws them outward to the ground, like the cords of a bell-tent; but the leaves are left on the stems, and remain fresh for some time. The upper part is then fitted together, and the leaves and moss make a beautiful umbrella-shaped roof. In front of the central building, the birds clear a space about a yard in diameter, which they cover with moss, after removing all stones and weeds. On this moss carpet they arrange flowers and brilliant fruits in great variety, and of the brightest colors to be found. Showy fungi and elegantly colored insects are distributed about the garden and inside the tent, and when these lose their freshness, they are thrown away and replaced by others. The tent itself is about thirty-nine inches in diameter and eighteen inches high. The Papuans never disturb these bowers. They call the builder the "master-bird, or Tukan Robon," the "gardener," and say it is wiser than mankind,-and, judged by the Papuan standard, perhaps this estimate is a true one. In the gallery of one of the bower-birds, half-a-peck of decorations was found. Among these were a large white shell, four hundred shells of a brightcolored snail, flints and agates, red seedpods and seeds, and the bleached and shining bones of animals. If for shells we read mother-of-pearl; for snail-shells, cowries; for flints and agates, agates and malachite; for seeds, beads; and for bones, ivory, where does the taste of beauty in the bird differ from our own ?— Spectator.

AT a time when the world is filled with excitement over the latest discovery by Koch, it may not be without interest to review the progress of micro-biological study, and direct attention more particularly to the place where the chemist unexpectedly struck the high road of medicine, and came upon the first stray wanderers pursuing corresponding researches among the intricacies of the lower fungi.

Within this third realm," as Dumas calls the borderland between the animal and vegetable kingdoms, we must allow our minds to carry us into the region of the invisible, for we have to realize the fact that the air round about us is crowded with the germs, in every stage of vitality, of small organisms which are noiseless, intangible, unseen. While sleeping, waking, eating or drinking, they steal

so insidiously upon us that we are unconscious of their presence until illness gives the first note of warning.

But before plunging deeper into the still unfathomed depths of the causes of disease, let us for a moment try to form some slight conception of what constitutes primitive life. As we are going back to the earliest beginnings of living things we must start from the thin line which divides the animate from the inanimate. To raise one of those primitive froms of life from its slimy home we have only to tie a piece of muslin over a water faucet and allow the water to trickle slowly through it for a few hours. If we examine under the microscope the scum which remains we bring before our vision one of the oldest inhabitants of our globe, the celebrated Amaba.

Looking like a bit of animated jelly, it is composed of a single cell, it is perfectly transparent, and scarcely distinguishable under the microscope from the water in which it lives, moves, and has its being. It rolls itself onward, searching for mor sels of imperceptible food, which it draws into its transparent interior to digest at leisure. This curious little primitive being has everything to do for itself without any of the usual apparatus for doing it. To catch its food it has to improvise arms by protruding parts of its body out here and there, drawing them in again with perchance some little prey. It seems never at a loss, for without a stomach it digests, without lungs it breathes, and without sex it multiplies by dividing its minute body into still minuter portions. These, like the parent, become perfectly independent beings, and almost as soon as born-if I may say so give birth to others again. At the extreme other end of the biological scale we find that in man life also originates in a single cell, with the important difference that it divides and subdivides, and forms into clusters of cells, which form into layers, till in the final grouping of specialized cells we have the highest order of being.

Thus all living things throughout the animal and vegetable kingdoms are com

* Prudden's Story of the Bacteria.

Haeckel's Evoluton of Man. "The human organism, like that of the higher animals, exists for a short time in this simplest conceivable form. The entire human child, with all its great future possibilities, is in this stage only a simple ball of protoplasm-monerula.

posed of cells, springing in the first instance from one single cell. Now the infinitely small beings which do so much good, or may do so much harm, in our everyday lives, are all cells in their primitive condition, and although such ancient inhabitants of our globe, have only recently emerged from their obscurity to startle the world with the knowledge of their presence.

Where Pasteur first stepped in was to prove that not only did water teem with microscopic life which had long been under observation, but that the air around us was likewise filled with invisible germs of every kind some carrying on the business of scavengers; others of the utmost importance in the work and industries of man. Without laying claim to be the first discoverer of germs in connection with disease, he was the first to recognize the vast importance of these minute organisms in the economy of nature. It was while working at molecular physics that the germ theory took root in his mind, and caused him to pursue the studies on fermentation which eventually led to the investigation of ferment (zymotic) diseases affecting human beings, and cattle. He considered fermentations, properly so called, as chemical phenomena, co-relative with physiological actions of a peculiar nature, and regarded fermentation as a necessary consequence of the manifestation of life, when that life takes place without the direct combustion due to free oxygen. He argued that

all that has lived must die, and all that is dead must be disintegrated, dissolved, or gasefied; the elements which are the substratum of life must enter into new cycles of life. If things were otherwise, the matter or organized beings would encumber the surface of the earth, and the law of the perpetuity of life would be compromised by the gradual exhaustion of its materials. One grand phenomenon presides over this vast work, the phenomenon of fermentation.*

What, then, is the cause of fermentation?

In order to answer this profound question Pasteur devoted himself to the study of the microscopic beings, which he finally divided into two great classes, the aerobies and the anaerobies, those which require free oxygen for their existence, and those which are killed by the presence of free

* M. Valery Radot, Vie d'un Savant.