times met with in the warmer latitudes, gaily scudding before the gentle breeze, in compact order, and presenting a spectacle of singular interest and beauty.

One of the commonest of these sailbearing Acalephæ, and one which, during storms, is often thrown upon our own shores, is the Velella lata, in which the disc is of a fine blue colour, and has the cartilaginous plate in the form of a dorsal shield, with the delicate sail-membrane rising obliquely from its centre. In another division of the Cirrhigrades, the crest or sail is furnished with muscular bands, by means of which it can be raised or lowered at pleasure-a circumstance which has procured for the entire group the very appropriate designation of 'bargemen.' All these animals are small, and beautifully transparent. One of the best known is a curious little fellow, which, by the lofty rounded form of its body, has earned for itself the appellation Mitrata (mitred), although, if it have any ecclesiastical leanings at all in the matter of shape, it approaches most nearly perhaps to that of the odd-looking crinison skull-cap of his Eminence the Cardinal.

All the Cirrhigrada have the stomach in the form of an inverted flask hanging from the under surface of the body, with the mouth at its lower extremity. The cirrhi immediately surrounding the latter are adapted rather for prehension than locomotion, and are busily employed in seizing the minute prey, as the graceful voyagers calmly sail along the surface of the deep.

The fourth and last section of the jellyfish includes the animals which Cuvier termed Hydrostatic Acalephæ. According to the classification now adopted, they constitute the order Physograd, so named from the inflated air-bags with which they are provided, and by means of which, in part at least, they effect locomotion. In this section of the Acalephæ, we entirely lose the circular radiate form by which the previous orders are distinguished, and have, instead, a sort of lateral symmetry or correspondence between the two sides of the animals composing it. There are two great divisions of the Physograda which until recently were regarded as distinct sections of the Acalephæ, and ranked as separate orders.

A well-known example of the first division is the Physalia, or Portuguese-manof-war of sailors. The body of this sin

gular jelly-fish consists of a large pearshaped air-bladder, beautifully tinted with blue, green, and rimson. It is surmounted by a fringed crest or sail of the richest purple, and has depending from it a cluster of variously-shaped tentacula, some of great length, and employed in the capture of prey, others short, tubular, and terminated by suckers, through which the Physalia, destitute of a true mouth, imbibes its food. This food consists principally of small fish; and the long tentacles by which they are caught are truly formidable implements. According to Mr G. Bennett, they can be coiled up within half an inch of the air-bag, and then suddenly shot out to the length of twelve or eighteen feet, twining round and round the body of the prey, paralysing it by means of their acrid secretion, and then contracting so as to bring it within reach of the tubular suckers. As in the case of the Velella, vast shoals of these animals are often encountered in the tropic seas, where the surface of the ocean is frequently crowded with their bright and glittering forms over an area of many square miles. It is said, that should danger threaten the Physalia while thus wafted along on the bosom of the deep, it can at once contract its sail, expel a portion of the contents of the air-bladder, and by condensing the remainder, descend in security to the depths below.

Naturalists have been sadly puzzled what to make of the animals which form the second division of this order. They are diminutive little creatures, and composed of two pieces which easily separate, and when detached will swim about independently for hours together. Hence arose the difficulty whether to regard these compound bodies as two animals united into one, or as one animal which, for a time, might be separated into two. Cuvier, and most zoologists following him, adopted the former opinion, regarding the two pieces as two independent animals. It has lately been very satisfactorily shown, however, that the two pieces do after all constitute but one animal, although our knowledge of these singular creatures (the Diphyde, or jelly-fish of a double nature) is still very incomplete. Considerable diversity of form prevails amongst them, and frequently also between the two portions of the same animal. They are so beautifully transparent as to be almost invisible in the water, and occur chiefly at great distances from the shore in the

seas of warm climates, where they abound in great profusion.

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Reference has already been made to the luminosity of some of the jelly-fish. All these animals, there is reason to believe, are endowed with the property of emitting light; and it is mainly to their agency that we owe the beautiful phenomenon known as 'the phosphorescence of the sea.' 'When,' says a writer before quoted, on a summer's evening the waves flash fire as they break upon the shore, or glow with myriads of sparks as they curl and froth around the prow of the moving ship, or under the blade of the striking oar, it is to delicate and almost invisible Medusa that they chiefly owe their phosphorescence.' It has never been clearly ascertained what organs are concerned in the production of this phosphoric light, nor has the most careful examination ever availed to detect the secretion itself, although there can be little doubt that the animals are enabled to exhibit the phenomenon at will. It is most frequently witnessed when the surface of the sea is ruffled by some gentle breeze; dead calms and very rough weather being alike unfavourable to its production.

Over all parts of the ocean alike, the waves are lit up at times with these animated fires; but in the warmer latitudes the spectacle assumes an aspect of extraordinary sublimity and splendour. 'Between the tropics,' says the venerable Humboldt, 'the ocean simultaneously develops light over a space of many thousand square miles. Here the magical effect of light is owing to the forces of organic nature. Foaming with light, the eddying waves flash in phosphorescent sparks over the wide expanse of waters, where every scintillation is the vital manifestation of an invisible animal world.' According to the enthusiastic accounts of voyagers, the appearance of the ocean on these occasions is grand and beautiful as it is possible to conceive. Far as the eye can reach, the crest of every wave, which during the day is white with foam, becomes transformed by darkness into a swelling ridge of light; while, here and there, where the billows dash with greater violence, the spray flies up, sparkling and glittering like a shower of stars, and, falling again, is lost in a sea of effulgence. Occasionally, too, while the more minute forms of the Acalephæ produce this diffused luminosity at the surface of the ocean, the larger kinds are seen below, illuminating

its mystic depths-some gleaming through the water with a pale and steady light, like submerged moons; others glowing with dazzling brightness, like balls of molten metal, or shooting by like the fiery meteors of the heavens above.

Nothing connected with the jelly-fish more truly deserves to be characterised as wonderful, than what has of late years been discovered with respect to their mode of reproduction. Two distinct modes of increase have been ascertained to prevail amongst these animals—one by the development of eggs; the other by the process of budding or gemmation. According to the latter mode, which was first observed in 1837 by Sars, a Swedish naturalist and clergyman, the young jellyfish sprout from the bodies of their parents like the leaf-buds of a plant, and after attaining to a certain stage of advancement, become detached, and swim away, to enjoy a free and independent existence. The singularity of this mode of increase is apt to be underrated, because of the insignificance of the creatures amongst which it obtains. Professor Forbes, in his elaborate work before quoted from, helps us to estimate the oddity of the process, by supposing it to be observed amongst animals somewhat more bulky, and higher in the scale than jelly-fish. Fancy,' he says, ' an elephant, with a number of little elephants sprouting from his shoulders and thighs, bunches of tusked monsters hanging, epaulettefashion, from his flanks, in every stage of advancement. Here a young pachyderm, almost amorphous; there one more advanced, but all ears and eyes; on the right shoulder a youthful Chuney, with head, trunk, toes, no legs, and a shapeless body; on the left, an infant, better grown, and struggling to get away, but his tail not sufficiently organised as yet to permit of liberty and free action!' The comparison seems grotesque and absurd, but it really expresses what we have been describing as actually occuring among our naked-eyed Medusæ.

It is to the development of the ova, however, that the chief interest pertains, the germs being now ascertained to pass through a series of the most remarkable transformations before assuming their mature form. The eggs are produced within the body of the jelly-fish in regular ovaries, whence they are transferred to a curious pear-shaped sack, appended to the fringe of the tentacula. Here they are

retained for a time, and then, the sack bursting, the embryos escape in the form of minute oval bodies, covered with cilia, and, to all appearance, a swarm of infusorial animalculæ. In this state the young brood remains for some days, sporting gaily in the water, and subsisting apparently in just the same manner as the animals they so closely resemble. In due course, however, one end of the germ begins to contract, and gradually is developed into a sucker-like base, whereupon each of the little creatures attaches itself to some fixed object, and becomes for awhile settled and stationary. And now a new character is assumed. The cilia, no longer needed, disappear. A cavity is formed at the upper extremity of the body, and, gradually deepening and enlarging, becomes at length a capacious mouth; around this four arms sprout forth, which being soon succeeded by four more, and these by another four, we have at length-from the egg of a jelly-fishan animal, which is to all appearance an ordinary hydra-form polype!

Nor is it in form alone that the correspondence holds. The disguised jelly-fish actively discharges all the functions of polype life, twirling its arms about to entrap prey, gorging the prey it secures, and ejecting the indigestible parts of its food through the mouth precisely as is done by the hydra itself. It has, moreover, all the hydra's power of renewing lost parts, and reproducing the entire body from a single portion; and, lastly, it multiplies itself, as do the true polypes, by buds or gemmules, so as often to produce a whole colony of similar beings. Add to all which, that the creature has been known to remain in the polype state for nearly two years; and no one can wonder that it should often have been mistaken for an animal in its mature form, without the remotest suspicion of its true character.

After the lapse of a considerable interval, however, important changes take place, and the extraordinary nature of the seeming polype soon becomes apparent. The body lengthens; its skin begins to shrivel; ring-like depressions appear around it; and in a little while the entire polype seems as if cut into a number of horizontal sections or slices, which turn up at the edges, and present the appearance of a pile of watch-glasses standing one within the other. Tentacles now grow out from each of the upturned edges, and the several sections become less and

less firmly attached to each other. In one or two days more, the connection between the different sections altogether ceases, and one by one, beginning at the top, they swim off, and become a brood of fully developed pulmonigrade jelly-fish.

It is upon these remarkable facts, and others of a like character, observed in the reproduction of some of the compound zoophytes, that Steenstrup, a Danish naturalist, has founded his novel doctrine of' Alternation of Generations.' According to this doctrine or hypothesis, the successive stages of advancement through which certain of the lower forms of life pass, are to be regarded, not as different phases of a process of metamorphosis or transformation, like that of the caterpillar into a butterfly, or the tadpole into a frog, but as distinct generations, in which the parent animal produces an offspring totally unlike itself, but which begets a progeny that returns in form and nature to that of the original stock; so that, as the originator of the idea himself puts it, the maternal animal does not meet with its resemblance in its own brood, but in its descendants of the second, third, or fourth degree of generation; and this always takes place in the different animals which exhibit the phenomenon in a determinate generation, or with the intervention of a determinate number of generations.'-('On the Alternation of Generations,' by J. J. S. Steenstrup. Publications of Ray Society.)

The aristocracy of the scientific world are pretty equally divided in opinion as to the tenability of the position thus assumed; some embracing it eagerly as a valuable truth, others of equal standing putting the thing aside as altogether fanciful and visionary. Attention has of late been directed to the subject afresh, by the offer of the Amsterdam Royal Academy of Sciences, of a prize of 600 florins for the best essay, illustrated by drawings from nature, critically discussing the entire question. Competitors for this prize will shortly have to send in their essays, so that, before very long, we may look for a full and authoritative exposition of the whole matter. Meantime, it is worth while to remember that the leading facts of the case are already fully established, and that, whatever interpretation may be put upon them, they must undoubtedly be ranked amongst the most wonderful phenomena which recent investigations in natural history have brought to light.

One other topic remains to be noticed, before bringing to a close our sketch of this interesting class of animals, The probable purpose and design of their existence. To suppose that these creatures occur in such teeming abundance in every part of the ocean, without having some distinct and definite task assigned them to perform, would but ill accord with what we see everywhere around us of the wisdom of the Creator, in the numberless adaptations and mutual relationships of the natural world. At the same time, it must be admitted that it is by no means certain what are the special services these animals render. No doubt the larger kinds, and especially such as are armed with the poisonous fluid before alluded to, serve as part of the police of the sea, and by capturing living prey, tend to check, and keep within proper limits, the abounding life of the waters. It has been conjectured again, that by the power which some of the jelly-fish possess of pouring from their bodies quantities of thick mucus or slime, they may be designed to replenish the sea with a kind of nutriment particularly adapted for the sustenance of new-hatched spawn, and to be thus made directly instrumental to the support of countless races which, but for them, might probably never have been

called into existence. In other cases, the Acalephæ themselves constitute the food of higher forms of life. The huge Cetacea of the Arctic seas are known to exist almost exclusively upon them, while they also constitute an important part of the support of numerous other tenants of the deep. In respect to the office discharged by the inconceivable multitudes of microscopic jelly-fish which people the ocean, there is perhaps less uncertainty than with respect to that of any others of the class. They act, there can hardly be a doubt, in concert with other minute beings with which the waters abound, in arresting the course of fugitive particles of decaying organic matter, and preventing them from passing away into the dead inert form of their original inorganic elements. They thus serve, so to speak, as the guardians and conservators of the organic world, appropriating the invisible atoms of perishing organic matter which have eluded the vigilance of all other beings; and assimilating them to their own substance, and re-adapting them to become the food of higher forms of life, thus turn back into the domain of animated nature what would otherwise have hastened to dissolution, and oppose an effectual barrier to the encroachments of the inorganic world.

F. C.

IT is pleasant to think of the sunny summer noonday, the hum of bees, and the brightness of the sky, now that the flowers are beginning to wither, and the latest of the leaves to fall. Albeit there may be a faint shade of sadness cast upon our thoughts, and though memory may have something more than the fading flowers to recall, still it is pleasant to go back again to the fresh fields beautiful with buttercups and daisies, to the breezy hillside where the sturdy heather and the broad-leaved ferns grow, to the woodland coverts where we have lain to look at the sunlight breaking through among the branches, making a very luxury of existence, and bringing back the happy wonts of early Paradise.' Nature yields us thus a twofold delight. Serene and soul-satisfying as is the enjoyment of her summer beauty, it is not more so than the remembrance of it when it has passed away. We hear the wind whistling in the chimney, and the shimmering light of the latter days of autumn tells us that, ere long, the whole aspect of the scenery around us will be changed, yet in our memory still live the blue-bells by the stream, and the wild anemone by the path that skirts it. The summer landscape lies within the heart, and all its tranquil joys again and again come back.

There is something analogous to this in the minds of persons we meet with in our daily experiences. There are writers, too, who seem to us as if they could not lose the recollection of their sunny time of life. We think of them always as happy youthful spirits who have had no fellowship with care. We cannot other wise think of them, for at that period when the days of most of us are in the sere and yellow leaf, they are as bright and joyous as of old. The form grows to manhood and womanhood, it even begins to give tottering tokens of Time's assaults, but the heart within it has never grown older-for fifty, or it may be sixty years, it is still the heart of boyhood or girlhood. Such persons look upon life through the dim eye of age as hopefully and as happily as they looked at it through the full laughing eye of youth. The inner freshness goes out to refresh and beautify all about them. To them the troubles of decaying nature seem but as the winter to

MITFORD.

us, when summer memories are brightest, and when the heart is filled with the quiet joys which they beget. One such person is represented in a book that now lies before us.* Protracted pain has shaken her, the shattered frame has been prostrated, and is prostrate now; yet, throughout the sunny days that have just gone by, she sat where she could see the roses peeping in at her cottage windows, and the wind waving the ripening corn on the distant fields-sat where the sunbeams could fall around her, and where the singing of birds could be heard. Thankful, cheerful, and loving-hearted, she sat there, and was wheeled to bed when the day declined. So passed another summer of a life that has been full of sunshinethe life of Mary Russell Mitford, one of the most delightful of modern English writers, one of the best beloved of them, and not much, if at all, below the most powerful in intellectual achievement. Many years have passed since the author of 'Our Village' produced some of the sweetest glimpses of English landscape that ever were given by the pen of a descriptive writer, and many a sketcher of rural scenery has got his first lessons in the art of observing from the faithful pictures which that book contains. To read it, is to be transported into the quiet of sylvan scenes-to ramble between the thick hedgerows and over the soft greensward, listening to the murmurous stir in the air, of leaves overhead, or of ringing laughter from the fields on either side. You miss not one characteristic feature of the lowland landscape as you peruse its pages. Nor could the men and women, and boys and girls who go through the life-drama of mirth and sadness, of love and sorrow amid such scenery, be appropriate elsewhere. They are native to the domain. 'Our Village,' as it is painted, is the only background which could have been painted for them, and there is so much of nature about them all, that we cannot choose but love the painter. The pleasant books by which Miss Mitford's name is best known ('Our Village' and 'Belford Regis') are now numbered among

The Dramatic Works of Mary Russell Mitford. 2 vols.-Reminiscences of a Literary Life. By MARY RUSSELL MITFORD. 3 vols.