Country Walks of a Naturalist with His Children Part 2

[Ill.u.s.tration]

WALK IV.

MAY.

"Papa," said w.i.l.l.y, "you once told me of a very beautiful little creature, almost too small to be seen by the naked eye, that lives in water, and builds its house out of the small particles of clay or mud that float therein. The bricks are not of the shape of house bricks, but quite round. Do you not think we can find some of these animals in the course of to-day's walk? I forget the name of the creature." I know what you mean; you are speaking of a microscopic animal called _Melicerta_. "Oh, yes, that is its name, now I remember." I have no doubt we shall be able to obtain specimens from the ca.n.a.l; so we will walk along the bank for a short distance and then get into the fields again. We must take with us a clear wide-mouthed bottle, and we shall soon see whether we have captured any specimens. These exquisite little creatures attach themselves to the leaves and stems of water-plants; they are most readily seen on the finely cut leaves of the water-b.u.t.tercup or spiked milfoil. The way to proceed is to place a tuft of this plant in the bottle and to hold it up to the light, and we shall soon see whether any Melicertae are there.

[Ill.u.s.tration: MELICERTA ON WEED.]

Here is plenty of water-b.u.t.tercup--a very interesting plant by-the-bye, and one which is subject to much variation; for when it grows in swiftly flowing water all the leaves are very long and hair-like, but in still water there are flattened leaves as well, and the hair-like leaves are not nearly so long. You see it is now in flower; a beautiful white ma.s.s it forms in small still ponds. "Well, but, papa," said May, "the flowers are white, and I thought all b.u.t.tercups were yellow." Nearly all the b.u.t.tercups have yellow flowers, but there are two British species which have white blossoms, namely, this one and the little ivy-leaved b.u.t.tercup, or crowfoot, as it is often called, which is found either in the water or near the water's edge. Though the ivy-leaved crowfoot is generally regarded as a species, I think it is only a variety of the one we are now looking at. Now I fish a plant out with my stick and nip off a tuft of hair-like leaves and pop it into the bottle. Have I anything here? No doubt the microscope would show countless numbers of minute animalcules, but I detect no Melicertae. Let us try again. I nip off another tuft. There! do you see one, two, three, four little things sticking almost at right angles to some of the leaves? No, you see nothing? Well, perhaps not, for your eyes are not so accustomed to these things as mine are, but I will take out my pocket lens; there, surely you see that one close to the side of the bottle, do you not?

Oh yes, you see what I mean; well, that is the case or house of a Melicerta, which animal I will describe to you, and when we get home we will look at it under the microscope. The case is about the twelfth part of an inch long and about the thickness of a horsehair, and of a reddish colour generally, though the colour depends on the nature of the material out of which the case is made. Let us sit down and put the bottle on this large stone, and I dare say some of the creatures will soon show their heads at the top of the tubes, for they are all indoors now; the disturbance caused in breaking off the bit of weed and putting it in the bottle has alarmed the Melicertae, and very quickly they sunk within their houses of clay.

[Ill.u.s.tration: MELICERTA, ON WEED, MAGNIFIED.]

Now I see one fellow slowly appearing at the top, after the manner of a chimney-sweeper, but certainly in a much more elegant form. There!

it has unfolded four flower-like expansions, of which the uppermost are much the largest. The animal shows only the upper part of its body, and I can see with my pocket lens that it is somewhat transparent and whitish. But my lens has not sufficient magnifying power to reveal more, so I must tell you what I have seen of Melicerta under my compound microscope. Each of these four leaf-like lobes or expansions is surrounded with very minute hairs, which can move with great rapidity in all directions; these you will remember are called "cilia," from the resemblance to _eyelashes_, for which cilia is the Latin word. The motion caused by these numerous cilia lashing the water brings currents containing particles of food for the Melicerta, and materials for his house. Mr. Melicerta "is at once brick-maker, mason, and architect, and fabricates as pretty a tower as it is easy to conceive." The mouth is situated between the two large leaflets, and leads to a narrow throat, in which are the curious jaws and teeth of the animal. Below the jaws are the stomach and intestine; so you see the Melicerta, though so minute a creature, has a complex structure. "You said, papa," remarked May, "that the little creature makes its own tube; how does it do that?" Upon the upper part of the head there is a small hollow cup, which is lined with cilia, and probably also secretes some sticky fluid to make the pellets of clay adhere together; the particles of clay and mud, having been brought to the s.p.a.ce between the leaflets by the action of the cilia, are conveyed to this little cup-shaped cavity, and are then worked about by the cilia within, till a round pellet is formed which completely fits the cavity. The little creature then bends itself down upon the tube and deposits the pellet upon it, then it raises itself up again and proceeds to form another brick, its jaws working all the time. "I wonder," said Jack, "how the little creature manages to set apart and put in its proper place the particles required for food and those required for brick-making; it would be funny if it sometimes made a mistake and put the clay in its stomach and the food in the brick machine!" It is curious, indeed, to know how the materials are put in the proper place; I suppose the Melicerta has the power to change the direction of the currents and thus to place the particles in their proper place. By rubbing a little paint, such as carmine or indigo, in some water and placing a drop upon the gla.s.s slide with the Melicerta, these currents may be readily seen; and I have more than once seen rows of coloured bricks, red or blue, which the animal moulded and then deposited on the tube! We will take the bottle home, and if you have patience I doubt not I shall be able to show you a good deal of what I have been describing; but you must have patience, for, as an excellent naturalist has said, "The Melicerta is an awkward object to undertake to show to our friends, for, as they knock at the door, she is apt to turn sulky, and when once in this mood it is impossible to say when her fair form will reappear. At times the head is wagged about in all directions with considerable vehemence, playing singular antics, and distorting her lobes so as to exhibit a Punch and Judy profile."[B]

Hark! what is that bird singing so sweetly and with such animation in the hedge? Do you hear? It is the dear little sedge-warbler; often, indeed, heard, but not so often seen, for it is fond of hiding itself in bushes or sedges. The sedge-warbler, like the migratory warblers generally, comes to us in April and leaves us in September. How often have I listened with delight to its music when returning home quite late at night in summer months! If the bird stops its music for a few moments, you have only to throw a stone among the bushes and the singing commences again. I am not clever in describing musical sounds, and I cannot describe that of the sedge-warbler, nor can I always distinguish it from the song of its near relative the reed-warbler.

Both imitate the songs of other birds, and their incessant warblings and babblings at night cause them to be often mistaken for nightingales. I have generally found the nest of the sedge-warbler on the ground, on a tuft of coa.r.s.e gra.s.s or sedge; the nest of the reed-warbler is supported on four or five tall reeds, and is made of the seed-branches of the reeds and long gra.s.s wound round and round; it is made deep, so that the little eggs are not tossed out when the reeds are shaken by the high winds.

[Ill.u.s.tration: NEST OF REED WARBLER.]

Hark! there is the cuckoo; how clearly he utters "cuckoo! cuckoo!" He is not far away. Some people can imitate the well-known note so well as to deceive the bird and bring it near the place where they are hiding. Your Uncle Philip only the other day made a cuckoo respond to him; had the day been calm instead of windy, he would, no doubt, have induced the bird to come close to us. There he goes with his long tail, flying something like a hawk. You should remember the rhyming lines about the cuckoo's visit to this country:

In April, Come he will.

In May, He sings all day.

In June, He alters his tune.

In July, He prepares to fly.

Come August, Go he must.

"I think you said, papa," said May, "that it is only the male bird that utters the cuckoo note; what kind of a voice has the female?" I have never heard the note of the female cuckoo. Mr. Jenyns says, "The note of the female cuckoo is so unlike that of the male, which is familiar to every one, that persons are sometimes with difficulty persuaded that it proceeds from that bird. It is a kind of chattering cry, consisting of a few notes uttered fast in succession, but remarkably clear and liquid." Very curious are the habits of the cuckoo. Unlike most other birds, they do not pair; you all know, too, that cuckoos make no nests, but lay their eggs one by one in the nests of various other birds, such as those of the hedge-warbler, or hedge-sparrow as it is generally but wrongly called, robin, white-throat, and other birds. It is probable that the same cuckoo does not go twice to the same nest to deposit her egg. What a curious exception is the case of the cuckoo to the instinctive love of their offspring observable in almost all birds! After the eggs are laid the parent bird has no further trouble with them; no period of incubation to bare the breast of the brooding bird; no anxiety about her young ones, as some idle, wanton lad hunts amongst the trees and bushes, destroys both nest and eggs, or tortures the helpless fledglings!

"But, papa," said w.i.l.l.y, "how does it happen that the young birds hatched in the same nest with the young cuckoo always get turned out of it." The cuckoo, being much the larger and heavier bird, fills up the greater part of the nest, consequently the smaller fledgling companions get placed on the sides of the nest, and partially also on the back of the young cuckoo; when, therefore, the latter stands up in the nest he often lifts up on his back one of the small companions, who thus gets thrown headlong to the ground. This seems to me to be the mode in which the ejection sometimes takes place, till at last the young cuckoo is left sole possessor of the nest, and of course gets all the food; at the same time I ought to say that some naturalists attribute a murderous disposition to the young cuckoo, and say that the other inmates of the nest are maliciously thrown out. Others, again, say that the foster birds throw their own young ones out. It is certain that the young are sometimes treated thus, for they have been seen on the ground when the young cuckoo was too small to eject them itself.

[Ill.u.s.tration: CUCKOO.]

"But why do not cuckoos make nests and sit on their eggs like other birds?" said Jack. Such a question is more easily asked than answered; nevertheless I hope you will always try to discover reasons for things. "It is now," writes a celebrated naturalist, "commonly admitted that the more immediate and final cause of the cuckoo's instinct is, that she lays her eggs, not daily, but at intervals of two or three days; so that if she were to make her own nest and sit on her own eggs, those first laid would have to be left for some time unincubated, or there would be eggs and young birds of different ages in the same nest. If this were the case the process of laying and hatching might be inconveniently long, more especially as she has to migrate at a very early period, and the first hatched young would probably have to be fed by the male alone." The cuckoos come to this country about the middle of April; the male birds arrive before the females. Whether this arrangement is ungallant conduct on the part of the gentlemen birds, who prefer to come alone, or whether, just when the gentleman cuckoo is ready and almost impatient for a start, her ladyship has all at once discovered some important matter that ought to be finished before leaving the country, some adjustment of her dress, some tiresome feather that will ruffle itself up in spite of every effort to keep it smooth, I know not, but the fact remains, that my Lord and Lady Cuckoo do not travel together. Let us suppose that both s.e.xes have arrived in this country, we will say about the 23rd of April. It is natural they want a little time to look about them; at any rate, no egg is ready for being sat upon till some weeks after the arrival of the birds, say the 15th of May. The eggs require fourteen days' setting before they are hatched; this brings the date to the 29th of May. The young ones will require three weeks in the nest and constant feeding all the time; we now arrive at about the 20th of June, when the young ones would be ready to leave the nest. But they want five weeks' more feeding by the parents, after they leave the nest, before they are able to provide for themselves; this would bring the date to about the 25th of July, when there is hardly a parent bird in the country; they have left for other parts of the world. "Oh! but, papa," said w.i.l.l.y, "you said in the lines you told us to remember--

In July, He prepares to fly.

Come August, Go he must.

And now you say the cuckoos leave before the end of July. I think you must have made a mistake somehow." I am glad that you have found out the error, if it is one. Old rhymes are not always to be trusted; but I suspect that the couplet "Come August, go he must," means to imply that the cuckoo does never really stay so late with us. I must not, however, forget to tell you that it is the old parent birds that leave us early; young birds remain till September, and even October, but they have not by that time acquired the cuckoo note. If you ask why cannot the old cuckoos stay with us a little longer, and then all go away together as a family party, young and old, in September, instead of being in such a hurry, I have only to say that it is the fashion amongst cuckoos, and of course cuckoos, like certain other animals, must be in the fashion. This is Dr. Jenner's explanation of the peculiar habits of the cuckoo in respect of its eggs. I am not prepared to say whether or not it is sufficient to explain them. The cuckoo's egg is very small when compared with the size of the bird; it is of a pale grey tinged with red.

"But how does the cuckoo's egg get into some of the nests?" asked w.i.l.l.y; "for some of the nests in which the cuckoo's egg is found are too small to allow the cuckoo herself to enter to lay her egg." You are quite right; I believe it has been proved that the cuckoo lays her egg on the ground, and carries it in her bill into other birds' nests.

[Ill.u.s.tration: HORSE-TAIL.]

"Oh! papa," said Jack, "what is this curious plant that grows so abundantly on the gra.s.s here? I know it well by sight, but do not know its name." It is a spike of horse-tail; see how the stem is marked with lines, and how curiously jointed it is, and quite hollow except where the joints occur. The fruit is borne at the top of the plant (_a_); see, as I shake it, what a quant.i.ty of dust comes from it; this dust is the fruit, or spores as they are called; each spore is of an oval form, with four elastic threads. If I were to put some of this dust on a gla.s.s slide, and look at it under the microscope, I should see a curious sight. The four threads would be spread out, but if I were to breathe on the gla.s.s, these threads would coil themselves round the oval body; but as soon as the effect of the moisture had pa.s.sed away, the threads would shoot out again in the same position as they were at first, causing the spore to leap as if it were alive.

The stems are of two kinds, fertile and unfertile; the one you have in your hands is a fertile spike, and appears only in the spring; the unfertile ones have no dust-like fruit, and have numerous jointed branches growing in rows, or whorls as they are termed, round them; they remain throughout the summer, and in some places form quite a thick cover. Feel how rough the stem is; this is due to the presence of a quant.i.ty of silex or flint in it; on this account some of the species are used for polishing purposes. One kind, under the name of "Dutch rushes," is imported from Holland, being used for polishing mahogany, ivory, metal, &c. The horse-tails for the most part grow in moist ground, in ditches and on the borders of lakes; some, however, are common in corn fields and on the roadside. In this country they do not attain a height of more than a few feet, but in tropical countries one or two species grow to the height of sixteen feet or more.

[Ill.u.s.tration: HYDRae, ON ROOTS OF DUCKWEED.]

Now for a dip with the bottle in this pond. I will try and catch a few Hydrae. Strange animals, indeed, they are, and strange is their history; but let us catch a few first. Nothing yet in my bottle like a hydra. Ah! now we have one or two. You see a small creature sticking to the stem of a bit of duckweed; around its mouth are five or six little projections. At present they are contracted; but the hydra is able to lengthen them out, when they appear as long, thin lines, which are used as the creature's fishing-lines; it is not much larger than a pin's head at present, but it can stretch its body out as it does its lines. I will take a handful of duckweed, and put it, dripping wet, into this bag, and when we get home we will place the whole in a gla.s.s vessel full of water. In the course of half an hour or so, we shall, no doubt, see several hydrae, probably of different species, in various att.i.tudes--some hanging loosely down, others erecting themselves in graceful curves and throwing out their arms or tentacles many times longer than their bodies; others shooting up their arms right above their heads; others contracted, looking like miniature dabs of jelly; others attached head and tail to the side of the gla.s.s; others floating on the surface of the water, their tail-ends sticking out and serving to keep them from sinking; some of a beautiful gra.s.s-green colour, others light brown or flesh colour, others almost white, others red. These creatures may be cut into several parts, yet each part will grow again into a perfect animal; young ones bud out of the sides of the parents. Some have said that they can be turned inside out, and find no inconvenience whatever from the operation. "But how,"

asked w.i.l.l.y, "could anybody manage to turn so small a thing as a hydra inside out?" It does seem an impossible task, I confess, and a man must have much skill and patience to enable him to accomplish it.

However, I will give you the description of an attempt made many years ago by a celebrated naturalist of Geneva, named Trembley, who made the hydrae or fresh-water polypes a study for many years. This is what Trembley says:--"I begin by giving a worm to the polype on which I wish to make an experiment, and when it is swallowed I begin operations. It is well not to wait till the worm is much digested. I put the polype, whose stomach is well filled, in a little water in the hollow of my left hand; I then press it with a small forceps nearer to the tail end than to the head. In this way I push the swallowed worm against the mouth of the polype, which is thus forced to open, and by again slightly pressing the polype with my forceps I cause the worm partly to come out from its mouth, and thus draw out with it an equal part of the end of its stomach. The worm, coming out of the mouth of the polype, forces it to enlarge itself considerably, especially if it comes out doubled up. When the polype is in this state, I take it gently out of the water, without disturbing anything, and place it on the edge of my hand, which is simply moistened, so that it may not adhere too closely. I oblige it to contract more and more, and this also enlarges the stomach and mouth. The worm then is partly coming out of the mouth, and, keeping it open, I then take in my right hand a hog's bristle, rather thick and without a point, and I hold it as one holds a lancet for bleeding. I bring its thickest end to the hind end of the polype and push it, making it enter into its stomach, which is the more easily done as in that part it is empty and much enlarged.

I push on the end of the hog's bristle, which continues to invest the polype. When it reaches the worm, which holds the mouth open, it either pushes the worm or pa.s.ses by its side, and at last comes out by the mouth, the polype being thus completely turned inside out."

[Ill.u.s.tration: HYDRA, WITH YOUNG ONES BUDDING OUT FROM ITS SIDE.]

Very strange, indeed, to think that animals with the wrong side outermost should continue to eat, grow, and multiply, as Trembley a.s.sures us his specimens did, though, perhaps, we shall not wonder that they often tried to turn themselves back to their original condition, and with success, unless Trembley took steps to prevent them. There are other strange things recorded of the fresh-water polypes, as that different individuals can be grafted together without the slightest inconvenience to any of the parties, the joint-stock company of course being limited.

The hydrae live on small worms, larvae of gnats, water-fleas, and other minute creatures; they catch them with their tentacles or fishing-lines, and draw them to the mouth. It is maintained by many observers, with good reason, that these arms have the power of paralysing, in an instant, the worms they wrap themselves round. There are at least three well-marked species of hydrae to be met with in the ponds and ditches of this country. There is the green hydra, the light flesh-coloured or common hydra, and the long-armed hydra, the most interesting of all. See, there is the water-primrose, now in flower, with its delicate pink corolla and bright orange centre. Let us gather a few plants, and then return home.

[Ill.u.s.tration]

FOOTNOTES:

[Footnote B: 'Marvels of Pond Life,' by H. J. Slack, p. 92.]

WALK V.

MAY.

To-day we will go to Shawbury and try our luck with the trout. If the fish will not rise there will be plenty to observe, and I have no doubt we shall enjoy the day thoroughly; the wind is in the south-west and the day is cloudy; the May-fly is well out, and I think we have every chance of good sport. Let us look out our fishing-tackle and drive off at once to the river. How delightful it is to stroll by the river side and hear the rippling of the water; delightful, too, is the sensation of feeling at the end of your line the tugs and jumps of a good lively trout. I cannot resist quoting some lines from 'The Angler's Song,' which I think you will say are very pretty:

Merry in the greenwood is the note of horn and hound, And dull must be the heart of him that leaps not to their sound; Merry from the stubble whirrs the partridge on her wing, And blithely doth the hare from her shady cover spring; But merrier than horn or hound, or stubble's rapid pride, Is the sport that we court by the gentle river side.

Our art can tell the insect tribe that every month doth bring, And with a curious wile we know to mock its gauzy wing; We know what breeze will bid the trout through the curling waters leap, And we can surely win him from shallow or from deep; For every cunning fish can we a cunning bait provide, In the sport that we court by the gentle river side.

Where may we find the music like the music of the stream?

What diamond like the glances of its ever-changing gleam?

What couch so soft as mossy banks, where through the noontide hours Our dreamy heads are pillowed on a hundred simple flowers?

While through the crystal stream beneath we mark the fishes glide, To the sport that we court by the gentle river side?

For as the lark with upland voice the early sun doth greet, And the nightingale from shadowy boughs her vesper hymn repeat; For as the pattering shower on the meadow doth descend, And far as the flitting clouds with the sudden sunbeams blend; All beauty, joy and harmony, from morn to eventide, Bless the sport that we court by the gentle river side.

Well, here we are once more at the charming little village of Shawbury. How often, both as a boy and a man, have I wandered by the banks of the river Roden. What changes have taken place since my early rambles! Long familiar forms, companions in my fishing expeditions, have vanished; the mind fondly cherishes their memory, and recalls past hours of cheerful intercourse. We will put up the horse and carriage at the Elephant and Castle Inn and stroll away to the river.

Ah! here is a capital place. Now, Master w.i.l.l.y, there is no tree to interfere with your throw, so cast in just near that spot, quietly, carefully, anxiously; if there is a fish there he cannot resist your green drake. I recommend him the artificial before the fat natural fly. As Christopher North says--"Devouring ephemerals! Can you not suffer the poor insects to sport out their day? They must be insipid eating--but here are some savoury exceedingly ... they carry _sauce piquante_ in their tails. Do try the taste of this bobber--but any of the three you please." There, hold fast, w.i.l.l.y, for that's a good one. Bring him up carefully to the side; hold your rod erect; play him a little, for he is full of vigour. There! well done; I have got him in the landing net. Is not he a beauty? A pound weight, I'll be bound; and what condition! His flesh will be almost as pink as that of a salmon. Further down stream I managed to take a fish in very different condition; I took him where the river was rather muddy, and flowed very slowly. Just look at him, with a body lean and dark coloured, and an enormous head for so slender a body. "Oh! but, papa," said w.i.l.l.y, "what are these curious creatures crawling over him? Do look." Ah! I know them well; anglers call them trout lice. I will sc.r.a.pe off a specimen, and put him in the bottle. Now look at him. The body is nearly round, and almost transparent; colour rather green; it has four pairs of swimming feet, each pair beset with a fringe of hairs; a pair of foot-jaws; a small half-cleft tail; and a pair of fleshy circular suckers just in front of the foot-jaws, by means of which the little creature is able to attach itself, as a parasite, upon various fish.

It is a graceful little creature, and, as you see, can swim with great activity in the water; now it swims in a straight line, now it suddenly turns quickly round and turns over and over. It is known to naturalists under the name of _Argulus foliaceus_; I do not think it has any English name. It is found on many kinds of fish, and generally in greater abundance upon individuals that are in an unhealthy state; though these parasites often attach themselves to fish in good condition. The mouth is furnished with a long, sharp sucking-tube, by means of which the animal can pierce the skin of the fish it lives upon, and suck up the juices. We will take a few home, and I will show you the different parts of the creature under the microscope.

[Ill.u.s.tration: PARASITE (_Argulus foliaceus_) ON TROUT, NAT. SIZE AND MAGNIFIED.]