Part 20

It only adds to the interest of this phenomenon when we turn to our learned books on birds for an explanation of the origin of migration, the whence and whither of the long journeys by day and night, and find--no certain answer! This is one of the greatest of the many mysteries of the natural world, of which little is known, although much is guessed, and the bright September nights may reveal to us--we know not what undiscovered facts.

I see my way as birds their trackless way. I shall arrive; what time, what circuit first, I ask not; but unless God sends his hail Of blinding fire-balls, sleet or driving snow, In sometime, his good time, I shall arrive; He guides me and the bird. In his good time. Robert Browning.

GHOSTS OF THE EARTH

We may know the name of every tree near our home; we may recognise each blossom in the field, every weed by the wayside; yet we should be astonished to be told that there are hundreds of plants--many of them of exquisite beauty--which we have overlooked in very sight of our doorstep. What of the green film which is drawn over every moist tree-trunk or shaded wall, or of the emerald film which coats the water of the pond's edge? Or the gray lichens painting the rocks and logs, toning down the shingles; the toadstools which, like pale vegetable ghosts, spring up in a night from the turf; or the sombre puff balls which seem dead from their birth?

The moulds which cover bread and cheese with a delicate tracery of filaments and raise on high their tiny balls of spores are as worthy to be called a plant growth as are the great oaks which shade our houses. The rusts and mildews and blights which destroy our fruit all have their beauty of growth and fruition when we examine them through a lens, and the yeast by which flour and water is made to rise into the porous, spongy dough is just as truly a plant as is the geranium blossoming at the kitchen window.

If we wonder at the fierce struggle for existence which allows only a few out of the many seeds of a maple or thistle to germinate and grow up, how can we realise the obstacles with which these lowly plants have to contend? A weed in the garden may produce from one to ten thousand seeds, and one of our rarest ferns scatters in a single season over fifty millions spores; while from the larger puff-balls come clouds of unnumbered millions of spores, blowing to the ends of the earth; yet we may search for days without finding one full-grown individual.

All the assemblage of mushrooms and toadstools,--although the most deadly may flaunt bright hues of scarlet and yellow,--yet lack the healthy green of ordinary plants. This is due to the fact that they have become brown parasites or scavengers, and instead of transmuting heat and moisture and the salts of the earth into tissue by means of the pleasant-hued chlorophyll, these sylvan ghosts subsist upon the sap of roots or the tissues of decaying wood. Emancipated from the normal life of the higher plants, even flowers have been denied them and their fruit is but a cloud of brown dust,--each mote a simple cell.

But what of the delicate Indian pipe which gleams out from the darkest aisles of the forest? If we lift up its hanging head we will find a perfect flower, and its secret is discovered. Traitor to its kind, it has dropped from the ranks of the laurels, the heather, and the jolly little wintergreens to the colourless life of a parasite,--hobnobbing with clammy toadstools and slimy lichens. Its common names are all appropriate,--ice-plant, ghost-flower, corpse-plant.

Nevertheless it is a delicately beautiful creation, and we have no right to apply our human standards of ethics to these children of the wild, whose only chance of life is to seize every opportunity,--to make use of each hint of easier existence.

We have excellent descriptions and classifications of mushrooms and toadstools, but of the actual life of these organisms, of the conditions of their growth, little is known. Some of the most hideous are delicious to our palate, some of the most beautiful are certain death. The splendid red and yellow amanita, which lights up a dark spot in the woods like some flowering orchid, is a veritable trap of death. Though human beings have learned the fatal lesson and leave it alone, the poor flies in the woods are ever deceived by its brightness, or odour, and a circle of their bodies upon the ground shows the result of their ignorance.

MUSKRATS

Long before man began to inherit the earth, giant beavers built their dams and swam in the streams of long ago. For ages these creatures have been extinct. Our forefathers, during historical times, found smaller beavers abundant, and with such zeal did they trap them that this modern race is now well-nigh vanished. Nothing is left to us but the humble muskrat,--which in name and in facile adaptation to the encroachments of civilization has little in common with his more noble predecessor. Yet in many ways his habits of life bring to mind the beaver.

Let us make the most of our heritage and watch at the edge of a stream some evening in late fall. If the muskrats have half finished their mound of sticks and mud, which is to serve them for a winter home, we will be sure to see some of them at work. Two lines of ripples furrow the surface outward from the farther bank, and a small dark form clambers upon the pile of rubbish. Suddenly a spat! sounds at our very feet, and a muskrat dives headlong into the water, followed by the one on the ground. Another spat! and splash comes from farther down the stream, and so the danger signal of the muskrat clan is passed along,--a single flap upon the water with the flat of the tail.

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If we wait silent and patient, the work will be taken up anew, and in the pale moonlight the little labourers will fashion their house, lining the upper chamber with soft grasses, and shaping the steep passageway which will lead to the ever-unfrozen stream-bed. Either here or in the snug tunnel nest deep in the bank the young muskrats are born, and here they are weaned upon toothsome mussels and succulent lily roots.

Safe from all save mink and owl and trap, these sturdy muskrats spend the summer in and about the streams; and when winter shuts down hard and fast, they live lives more interesting than any of our other animals. The ground freezes their tunnels into tubes of iron,--the ice seals the surface, past all gnawing out; and yet, amid the quietly flowing water, where snow and wind never penetrate, these warm-blooded, air-breathing muskrats live the winter through, with only the trout and eels for company. Their food is the bark and pith of certain plants; their air is what leaks through the house of sticks, or what may collect at the melting-place of ice and shore.

Stretched full length on the smooth ice, let us look through into that strange nether world, where the stress of storm is unknown. Far beneath us sinuous black forms undulate through the water,--from tunnel to house and back again. As we gaze down through the crystalline mass, occasional fractures play pranks with the objects below. The animate shapes seem to take unto themselves greater bulk; their tails broaden, their bodies become many times longer. For a moment the illusion is perfect; thousands of centuries have slipped back, and we are looking at the giant beavers of old.

Let us give thanks that even the humble muskrat still holds his own. A century or two hence and posterity may look with wonder at his stuffed skin in a museum!

NATURE'S GEOMETRICIANS

Spiders form good subjects for a rainy-day study, and two hours spent in a neglected garret watching these clever little beings will often arouse such interest that we shall be glad to devote many days of sunshine to observing those species which hunt and build, and live their lives in the open fields. There is no insect in the world with more than six legs, and as a spider has eight he is therefore thrown out of the company of butterflies, beetles, and wasps and finds himself in a strange assemblage. Even to his nearest relatives he bears little resemblance, for when we realise that scorpions and horseshoe crabs must call him cousin, we perceive that his is indeed an aberrant bough on the tree of creation.

Leaving behind the old-fashioned horseshoe crabs to feel their way slowly over the bottom of the sea, the spiders have won for themselves on land a place high above the mites, ticks, and daddy-long-legs, and in their high development and intricate powers of resource they yield not even to the ants and bees.

Nature has provided spiders with an organ filled always with liquid which, on being exposed to the air, hardens, and can be drawn out into the slender threads we know as cobweb. The silkworm encases its body with a mile or more of gleaming silk, but there its usefulness is ended as far as the silkworm is concerned. But spiders have found a hundred uses for their cordage, some of which are startlingly similar to human inventions.

Those spiders which burrow in the earth hang their tunnels with silken tapestries impervious to wet, which at the same time act as lining to the tube. Then the entrance may be a trap-door of soil and silk, hinged with strong silken threads; or in the turret spiders which are found in our fields there is reared a tiny tower of leaves or twigs bound together with silk. Who of us has not teased the inmate by pushing a bent straw into his stronghold and awaiting his furious onslaught upon the innocent stalk!

A list of all the uses of cobwebs would take more space than we can spare; but of these the most familiar is the snare set for unwary flies,--the wonderfully ingenious webs which sparkle with dew among the grasses or stretch from bush to bush. The framework is of strong webbing and upon this is closely woven the sticky spiral which is so elastic, so ethereal, and yet strong enough to entangle a good-sized insect. How knowing seems the little worker, as when, the web and his den of concealment being completed, he spins a strong cable from the centre of the web to the entrance of his watch-tower. Then, when a trembling of his aerial spans warns him of a capture, how eagerly he seizes his master cable and jerks away on it, thus vibrating the whole structure and making more certain the confusion of his victim.

What is more interesting than to see a great yellow garden-spider hanging head downward in the centre of his web, when we approach too closely, instead of deserting his snare, set it vibrating back and forth so rapidly that he becomes a mere blur; a more certain method of escaping the onslaught of a bird than if he ran to the shelter of a leaf.

Those spiders which leap upon their prey instead of setting snares for it have still a use for their threads of life, throwing out a cable as they leap, to break their fall if they miss their foothold. What a strange use of the cobweb is that of the little flying spiders! Up they run to the top of a post, elevate their abdomens and run out several threads which lengthen and lengthen until the breeze catches them and away go the wingless aeronauts for yards or for miles as fortune and wind and weather may dictate! We wonder if they can cut loose or pull in their balloon cables at will.

Many species of spiders spin a case for holding their eggs, and some carry this about with them until the young are hatched.

A most fascinating tale would unfold could we discover all the uses of cobweb when the spiders themselves are through with it. Certain it is that our ruby-throated hummingbird robs many webs to fasten together the plant down, wood pulp, and lichens which compose her dainty nest.