Page images

pearing towards the middle of autumn. I become developed, and the faculty of The young are hatched from eggs in inspiring the atmospheric air is acquired, about fifteen days after their exclusion, for which the as yet aquatic animal may and remain for some time in a tadpole be observed to come to the surface, state, that is, with branchiæ for the respir- taking it into its mouth, and afterwards ation of water ; these, however, become discharging below the surface in the form obliterated with the development of true of a round bubble. The gills now begin lungs, so that, though the newt passes to become obliterated; the tail, too, now the greatest portion of its existence in less and less requisite for the purposes of the water, it is only at first that, like the locomotion, either aquatic or terrestrial, tadpole of the frog, its respiration is fish- begins to shrink; it ultimately disappears, like; afterwards, the atmospheric air is and the metamorphose is complete. The breathed, for which it often comes to the appearance and the habits of the animal surface. The food of the newt consists have undergone an according change of the larvæ of aquatic insects, worms, with the reversal of its physical constituetc., and it may be caught by means of tion; and it is fitted either to leap among a baited hook. During the winter, it the grass of the meadow, or swim in the hybernates, buried in the mud.

water, the atmospheric air being its sole The transformations which the newt element of respiration.

Surely this and the frog undergo in their organiza- marvellous process, performed with untion, from the tadpole to the perfect varying precision, cannot be unintereststate, are very curious, and those of the ing to the thoughtful inquirer into the latter may be now contemplated with laws that regulate the conditions of living ease, as these little creatures abound in beings; it bespeaks design, and a power every ditch and pond, and are easily which baffles human comprehension. procured. The egg of the frog is a We are surrounded with mysteries in mass of round nutritive jelly, having a creation; we see a little, we know a small black spot in the centre. By de- little, but beyond a certain point our grees this small spot enlarges, and ex- utmost mental energies fail to pass. hibits the appearance of a round head But we must not leave the water withto which a flattened tail is joined; this is out endeavouring to gain an acquaintance the tadpole, and in this form it is hatched, with other beings, the contemplation of and moves with celerity in its new ele- which will fill our minds with astonishment. At first a few filaments, or feathery ment. Let us take some of these small tufts, appear on the sides of the neck, as aquatic plants, with a little of the water

in which they float, to our home, for the purpose of more minute examination. We shall scarcely fail to find on the leaves some singular polypes, the first discovery of which appears to have been made by Leuwenhoek in 1703, about the same time that a correspondent of

the Royal Society made the same disin the annexed figure, which float covery in England, and described their loosely, and serve for the aeration of the singular mode of reproduction. In 1744, blood by the air which the water itself these polypes may be said to have been contains. These filamentous appendages rediscovered by M. Trembley, of Geneva, are, however, only temporary, and pre- / who made known to science their woncede the formation of proper gills, which derful properties, so repugnant to the are four in number on each side, and established notions of animal life, that closely resemble those of fishes. Thus many regarded the alleged facts as imorganized as a fish, the animal increases possible fancies. The polype to which in size; but in a few weeks, the hind legs we allude, is the hydra, of which four begin to make their appearance, first fresh-water species are known, hydra beneath the transparent skin of the trunk, viridis, hydra vulgaris, hydra fusca, at the origin of the tail ; these are suc- and hydra verrucosa. Of these, the first ceeded by the fore legs; their develop three are common in weedy ponds or ment goes on progressively until they slowly running streams; the two former, have acquired a degree of size propor- however, being the most abundant; the tionate to that of the head and body. fourth has been taken in Ireland. It was During this period, the lungs have also I while examining some aquatic plants that M. Trembley observed certain singu- | that the head part of a polype cut in two lar filamentous bodies adhering to their has been seen in a few minutes to exleaves, which at first he regarded as pand its tentacula, and catch prey as parasitic vegetables ; but a closer exami- usual. nation convinced him that they were capa- In the water of the rivers or clear ble of locomotion ; and he found also ponds, which it naturally inhabits, the that they preyed upon small insects or hydra is mostly found at the surface, or crustacea, and were attracted by light. adhering to plants exposed to the light; He now became assured that they were it is indeed influenced by the light, which animals, and, delighted with the discovery, it invariably seeks; and when several are commenced a series of diligent investiga- confined in a glass, they seek that side tions.

which is most illuminated. Hence, we The hydra, the most simple of organ- may suppose that a highly refined degree ized beings, consists of a homogeneous of nervous sensibility, of which we can gelatinous tube, contracted at one ex- have no definite idea, resides in their tremity, which may be termed its caudal, whole composition, giving them a sense and which is furnished with a minute to us unknown. They also feel, and this sucker, for the purpose of adhesion to power or property is peculiarly observaleaves or stems; the other extremity, of ble in their tentacula, which surround which the orifice may be regarded as the the mouth, and which are affected by mouth, is surrounded by a number of the contact of other bodies, or even the radiating, contractile filaments, (of singu- smallest particles. These polypes, unlar length in hydra fusca,) which serve like most others, are capable of indeas arms of prehension. In the hydra pendent locomotion, and can wander viridis, these filaments, or tentacula, are about in the water according to circumscarcely equal to, or do not exceed, when stances. Their usual mode of proceedelongated to their utmost, the length of ing along the stems or leaves of plants the body. On submitting one of these is, however, slow; fixing their caudal animals to microscopic examination, sucker, so as to attach themselves sewhich may be readily done, it will be surely, they bend the body down with a found to consist of a granular structure gentle movement, describing a semicircle, invested by albumen; but neither nervous, till the mouth touches the surface of the nor muscular fibres, nor vessels of any leaf, or whatever it be, on which they kind can be discovered by the most mi- are stationed; they then adhere by the nute attention; there are no rings as in mouth or the tentacula, unfix the caudal the worm, nor any organs of the senses. sucker, draw it close to the mouth, and The entire composition is gelatinous, with there fix it; they then elevate the body, minute granules intermixed. Yet the again bend it down and adhere by the animal is possessed of the powers of tentacula, and bring the caudal sucker up locomotion, appreciates the presence of to the mouth as before, and so on in light, by which it is sensibly affected, succession. and is highly predatory and ravenous, This mode of progression is so tedious, waging warfare with beings far more that a journey of a few inches requires complexly organized than itself; and is several hours; they have, however, a at the same time so tenacious of life, that more expeditious way, which consists of if divided longitudinally or transversely, a series of somersets ; adhering by the by means of a pair of fine scissors, or tentacula and the caudal sucker, they even cut into several parts, each part detach the latter, and instead of bringing becomes a perfect animal. A polype it up to the mouth, throw it beyond, as cut transversely in three parts requires far as possible, describing a semicircle, four or five days in summer, longer in which being affixed, the same revolution cold weather, for the middle piece to is performed by the head. Free in the produce a head and tail, and the tail to water, the hydra moves much more get a head and body, which they do pretty rapidly; suspended with its head downmuch in the same time; the head part wards, its caudal sucker acting the part appears to perfect itself sooner than the of a float on the surface, it is drifted rest. It is extraordinary, that polypes with the current of the water, or wafted thus produced grow much larger and are along by the breeze, or, grasping objects far more prolific than those not multiplied within its reach with its tentacula, it by artificial division. So little inconve- propels itself along; or, holding firmly nience do these operations seem to give, I by a stem or leaf, moors itself in a state

the case.

It appears that


of rest.

When alarmed, or touched with teeth, nor any other instrument roughly, the hydra shrinks, contracting that could pierce the skin. It appears, its body and tentacula into the form of a moreover, according to Trembley, that small globule, which might easily escape fishes refuse to swallow the hydra. The observation, had not its situation been hard shells of the entomostracous insects, previously noticed.

however, on which the hydra largely That creatures of such unsolid struc- preys, seem to be defended from the efture should not only be voracious, but fects of this poisonous excretion of their capable of seizing and swallowing quick enemy, and when by chance they escape, and active animals, as insects and their swim about unharmed. Baker, who carelarvæ, and even minute fishes, is calcu- fully studied the habits of these creatures, lated to surprise us: such, however, is says, that they seize a worm with as much While watching for its prey, eagerness as a cat does a mouse,

and the hydra remains with its tentacula adds, " I have sometimes forced a worm spread widely out and motionless, wait- from a polype the instant it has been ing till some luckless tenant of the water bitten (touched by the polype's mouth) comes in contact with them; the moment at the expense of breaking off the polype's an animal, fitted to become its prey, is arms, and have always observed it die brought into contact with one of these very soon afterwards, without one single filamentous arms, its course is instan- instance of recovery.taneously arrested, and notwithstanding a worm, on being seized, evinces, by the all its efforts to escape, it appears to be most violent contortions, which, however, fixed as if by some power too great to be are but momentary, every symptom of overcome; the tentacle contracts, others painful suffering; these are succeeded are brought into contact with the strug- by sudden death. It is, then, from this gling captive, it is gradually dragged to poisonous property possessed by the hy. the orifice of the mouth, which opens to dra that it is enabled to overcome the receive it, and forced into the digestive struggles of worms far superior to itself cavity, where it may be seen through the in power and activity; its arms transparent body of the hydra, until the to them deadly instruments, within the process of digestion renders it indistinct, grasp of which they become paralyzed giving a dull opacity to the transparent and deathstruck. body of the devourer. The power which It would seem that the granules of the the tentacles possess of thus arresting the gelatinous body of the hydra, from their animal's prey is not well understood. change of colour according to that of the M. Trembley attributed it to a viscid se- prey, perform some important office in cretion acting like birdlime; but it has the assimilation of the nutritive particles been observed, that when the hydra is of the food. The action of the digestive satiated with food, animals which then cavity upon the food received is very may be brought into contact with the rapid; but the digestive powers of this tentacula are not arrested, but easily stomach exert no influence on any part escape.

of the animal itself, as the tentacula, It cannot be doubted, that the hydra is which in the long-armed species (H. to be reckoned among poisonous crea- fusca) are frequently coiled round the tures, being endowed with the power of prey while undergoing digestion in the instantly killing the softer animals on stomach: nor does one polype of the which it preys. Smellie states that small same species, if swallowed by a larger water worms, which the polypus is accus- individual, appear to be subject to the tomed to attack, are so tenacious of life, operation of the digestive powers. On that they may be cut to pieces without one occasion M. Trembley saw a contest their seeming to receive any material between two of these creatures for the injury, or suffer much pain from the in- same prize, which both had seized, and cisions ; but the poison of the polypus both partially swallowed; the strife ended instantly extinguishes every principle of by the larger swallowing the smaller life and motion ; strange to say, no hydra, together with the subject of their sooner has the mouth of the polypus mutual contention. The fate of the touched this worm than it expires. No smaller hydra he regarded as certain ; wound, however, is to be perceived in but no. After the devourer and the the dead animal. By experiments made devoured had mutually digested their with the best microscopes, it has been mutual captive, the swallowed hydra was found that the polypus is neither provided | disgorged from his imprisonment alive

and sound, and apparently without hav- never find it. They are procuring food ing suffered


for their nestlings; this consists of the The reproduction of these animals is larvæ of aquatic insects and the fry of plant-like, by gemmules or buds, which small fish, such as the minnow, and it is sprout indifferently on any part of the in quest of these that they plunge so animal's body, gradually assume their frequently beneath the water. "How the true form, and become detached and bird manages to keep itself submerged independent. The annexed sketches and proceed in its search of prey, is not present us with the two species of this very easily explained, but that it does

so is undeniable.

In the summer of 1839, I had an opportunity, as indeed I have had many times before, of narrowly watching the habits of these birds, which are common along the trout streams that run through the rock-belted and romantic dales of Derbyshire. Often and often have I watched them plunge in and reappear at a considerable distance, unwet, and then flit a few yards further, settle on a stone or crag, and again plunge and emerge as

before; but whether th :y walk at the singular polype. 1. The green hydra, bottom deliberately, (an unlikely mode) (hydra viridis,) in various positions, the

or proceed by the action of their wings, lowermost showing it gorged with food. (an opinion to which I incline,) I never

could positively determine; but where the water has been too shallow to cover them entirely, I have remarked their wings rapidly vibrating. The nest of these birds, composed externally of moss and green lichen, and lined with decayed leaves, is generally hidden in the fissure of some rocky bank overhanging the stream, or between the interstices of narrow stones. I observed one, in 1839, in the fissures beneath the rude stones of a small bridge across the Wye, near Buxton, and another in the ruins of an old water mill, among which the stream was dashing rapidly along. The eggs, five in number, are of a clear white :

the young leave the nest before being 2. The long-armed hydra, (hydra fusca.) able to fly with perfect facility, but even Both species are of the natural size. then, dive with great promptitude and

But you are, perhaps, tired with this apparent facility. long account of a minute creature, and There flits another tenant of the river, wish to contemplate beings of other races, rapid and direct in its flight as an arrow, in the habits of which you take more and glancing as it passes, like burnished delight. See that little bird on the stone metal in the sun. It is the kingfisher. which juts out in the middle of the rapid (Alcedo ispida.) It is also a diver in stream. It is the water ouzle, or dipper, pursuit of its prey, which consists almost (cinclus aquaticus. Beckst.) Mark exclusively of small fish, which it takes how it suddenly dips down its head, and as they rise near the surface, darting jerks its short erect tail; there, it has impetuously upon them, and carrying plunged into the water, and disappeared ; them to some favourite perching place, do not fear for its safety, it has again then to be eaten or taken to its young. made its appearance, and is perched by Having secured its prey, the kingfisher the water side ; it will soon dive again, carries it to land, and kills it by beating if we do not disturb it. There flies its it against a stone or the stump of a tree, mate: be sure its nest is near, but unless on which it may rest, and then swallows we watch the pair to their home, we shali | it whole the bones and undigestible

[ocr errors]


parts being rejected in the form of small | of Scotland; it feeds upon such insects pellets by the mouth, as is the case with and their larvæ as frequent and injuré the owl and other carnivorous birds. It the bark of trees, on which account it rears its young in a deep hole, running deserves protection : but seeds, and the diagonally upwards, and excavated in the kernels of the filbert and hazelnuts, soft steep bank of the river; sometimes also form part of its diet, and hence it takes possession of the deserted bur- it is capable of maintaining itself during row of a water-rat, enlarging it to suit its the winter, partly, by searching out own convenience. It makes no nest, the larvæ concealed in the crevices of but the young are soon surrounded by the bark, and partly by the wild fruits the rejected pellets of fish-bones; they mentioned. The method of arriving are very voracious, and their continual at the kernel of the hazel nut, or filbert, cry for food often leads to their discovery. is very ingenious, if such a word be As soon as fledged, they acquire the me- permitted, as applicable to the directions tallic brilliancy of their parents, a cir- of instinct. It first detaches the nut cumstance wisely ordained, for this bur- from the husk, or envelope, by means nished surface is requisite for enabling of its bill ; it then fixes it firmly in the plumage to throw off the water, so the crevice or chink of a tree, and hamas to prevent it from becoming saturated | mers it with its bill, repeating its strokes by diving; and by this means alone can until the shell is broken : a convenient the young birds procure their own food, place for this purpose is generally rewhich they are thus enabled to do as sorted to time after time; a hoard of soon as they can fairly fly.

refuse nut shells accumulating in the But let us now pass into the wood, for cavity or spot where the operation is the day is beginning to be hot, and the carried on. The nuthatch breeds in the leafy trees will form a pleasant shade. holes of trees, often appropriating the There goes the squirrel; how nimbly he deserted habitation of a woodpecker; ascends that smooth-barked beech; his and when the orifice is larger than nemate is probably with her young in their cessary, it narrows the entrance with nest; you may see it like that of a bird, mud or clay, and gravel, mixed together, in the fork of those tall branches, almost and plastered on the margin of the concealed by the foliage and thick boughs. opening, very neatly, so as to form a The nest of the squirrel is very curious, barricade, leaving an aperture just sufand it is remarkable that it should so ficient for its own ingress and egress. much resemble those of the feathered From this circumstance, has arisen one

It is composed of fibres and twigs, of its names among the French, that of curiously intertwined and lined with mason woodpecker. The nest is comleaves and moss. The young are three posed of dried leaves, artlessly put toor four in number, and remain associated gether; the eggs are five in number, with their parents till the following greyish-white, spotted with reddish• spring, when they separate and choose brown. The female sits very close, their mates; the male and female remain and is resolute in the defence of her attached and occupy the same tree for nest, hissing like a snake, and striking many seasons, having around it a little violently with her bill. The call note territory of their own, in which they of the nuthatch in spring is a loud, seek their subsistence.

shrill whistle. Observe that pretty bird which is now There is another little bird, creeping so nimbly running round and up the mouse-like around the bark of that pree, trunk of the fine tree before us: few which it so closely resembles in the birds display more activity or address than brown colour of its plumage, that did bark-climbers ; in this respect this bird not its movements betray it, it might even exceeds the woodpecker, as it is not easily be passed by unnoticed. It is only capable of ascending, but of descend- termed the creeper (Certhia familiaris) ing also; its tail, however, is flexible, and from its actions, and may be approached never used as an assistant in climbing, very nearly; watch it, see how it asas it is by the latter. The bird in ques- cends, winding spirally round the trunk; tion is the nuthatch (Sitta Europæa.) it cannot descend like the nuthatch, and The nuthatch is not uncommon in old therefore generally begins its travels woods, throughout a great part of our up the tree, in quest of insects, from the island; but is not found either in Corn- lower part of the trunk, using its stiff, wall, or in the more northern districts pointed, and deflected tail as a support


« PreviousContinue »