organisation and mode of growth. This discovery is the subject of a luminous paper, illustrated by eighteen figures from Mr. Bowman's pencil, in the sixteenth volume of the Linnean Society's Transactions.

In his highly interesting paper, the author details, with much clearness and precision, the result of his investigations on the organisation of this singular plant; and as they exhibit some striking exceptions from the general laws of vegetable physiology, not hitherto known, we shall present them to our readers as fully as our limited space will allow, and illustrate them by several of the original drawings confided to us by the liberality of the council of the Linnean Society.

It has long been known, that every part of the Lathræ a Squamària, except the flower-stems, is at all times strictly subterraneous; but we are not aware that any botanist has hitherto detected the nature of its parasitical connection, or the anomalous structure of its leaves. It may indeed be said to set the ordinary laws of vegetable life at defiance, even in its infancy; for no sooner has the embryo plant emerged from its cotyledons, than, instead of seeking the surface of the soil, it takes a downward direction, till it comes in contact with the roots by which it is nourished, after which it spreads horizontally among them. Its real root, it appears, is spindle-shaped and branched, terminating in forked fibres; which however do not draw moisture from the soil in the ordinary way, but are furnished at and near their extremities with very minute tubers, which fix themselves on the roots of trees and extract their juices. Similar tuberiferous fibres are copiously produced on the subterraneous stem between the imbricated scales. The tubers, though not larger than a small pin head, are exceedingly numerous, hemispherical, and of a succulent and tender texture. When fixed on the root, they throw down a funnel-shaped process or tap, which penetrates through the cortical layers into the alburnum (where the sap is in the greatest energy), and com

municates with a system of vessels of a jointed or beaded structure. These vessels traverse the substance of the tuber, and convey their stolen contents along the connecting fibre for the support of the parasite. The annexed figure (fig. 30.) is a perpendicular section of a tuber, highly magnified, showing the insertion of its tap-shaped base into the alburnum.

Not less wonderfully constructed and admirably adapted for their situation and office are the imbricated scales, or leaves, of the subterraneous stem, which, in size, shape, and colour, very remarkably resemble the human teeth, and have suggested its various names of Dentària, Squamària, and toothwort. These have generally been considered as roots, or scaly appendages to the roots; but Mr. Bowman has proved by numerous minute and delicate dissections under the microscope, illustrated by a series of beautiful and highly magnified drawings, and by a description and reasoning which we regret our space will not allow us to follow through all their details, that they are real leaves, adapted by their peculiar organisation for their subterranean situation, where, with the ordinary vessels of these organs, they could not have performed their functions. We shall endeavour, with the assistance of the drawings, to make this intelligible, after giving the author's preliminary glance at the usual process of vegetable life. "By laws which almost universally prevail in the vegetable kingdom, plants imbibe moisture from the soil by means of their radical fibres, and gases and moisture from the atmosphere through the medium of pores in the cuticle of their leaves. These elements are conveyed into the parenchyma, where innumerable and inconceivably delicate organs, stimulated by light and heat, throw off the oxygen, and retain the hydrogen and carbon. These essential ingredients at once produce the green colour, and are converted, by a mysterious and hidden process, into the several substances of the vegetable body." The succulent interior substance of the leaf of the Lathræ'a is pervaded longitudinally by a number of parallel cavities or chambers, of nearly its whole length, and whose sides are full of ridges and hollows like the human ear. The entire inner surface of these cells is thickly beset with innumerable papillæ or glands, each fixed on a pedicel, and so minute as not to be discernible without a good microscope. A longitudinal section of the leaf and one of its cavities is shown in the annexed 31

figure (fig. 31.), and a cross section exhibiting all the cavities divided in the middle, with their papillæ, at fig. 32., all much magnified. The only opening into the cells is between the involuted lower portion of the leaf and the leaf stalk, and is so narrow and completely concealed as to elude observation. It may, however, be detected in a thin longitudinal section of the leaf, and is seen in fig. 32. As the cuticle of the scales is not perfo

rated by any absorbing or perspiring pores, the author con

32

tends that their office is performed by the papil læ, and therefore that the imbricated scales are real leaves.

"In the case of the Lathræa, where they

(the leaves) are destined to perform their functions, not only in the dark, but buried in the earth, such an arrangement (the general law) would have been inexpedient; it is therefore substituted by another, admirably adapted to their peculiar circumstances and situation. Had the cuticle been furnished with air valves, the soil would have continually clogged and impeded their office; they are therefore removed by a contrivance, as beautiful as wise, and placed within the convoluted chambers excavated for them in the interior of the leaves, where they perform, securely and unseen, their destined office."

In the course of this able and interesting paper, the author dissents from the general opinion that the sickly colour of this and other parasites is to be attributed to their growing in the shade, as some suppose, or is a consequence of their parasitical condition, as Linnæus asserts, or of both combined; and maintains that the total absence of green arises, at least as much, from their wanting true leaves and a cuticle perforated with absorbing and perspiring pores. To support this view, he instances two parasites of British growth: one of which, Cuscuta europæ'a, dodder, is destitute of leaves, and has not a tinge of green, though growing in the full light; while the other, Viscum álbum*, mistletoe (perhaps the most strictly parasitical plant we have), is furnished with leaves, and is green.

* As connected with this subject, and as exciting to further research on the plants adverted to, it may be worth the space here to present a remark which Mr. Bowman expresses in a note at the foot of p. 410.:

"I have observed that the mistletoe dies with the tree on which it grows; and, from a notice in the Magazine of Natural History, vol. ii. p. 294. [by our correspondent L. E. O.], it seems that the Lathra a Squamària does so too. It has long been doubted whether Listèra Nìdus àvis [Neóttia Nidus àvis of Swartz] be strictly parasitical. Whatever it may be in the earlier stages of its growth, it certainly is not so in its more advanced state. If it be carefully got up in a clod, and the soil afterward washed from around it, the leaves of the central root or caudex may be seen to terminate in a short curved spur, which tapers to a fine point, and evidently is not attached to any other vegetable. The cuticle of the stem and it bracteas have no perspiring pores.'

REVIEWS.

ART. I. The British Naturalist; or, Sketches of the more interesting Productions of Britain and the surrounding Sea, in the Scenes which they inhabit; and with relation to the General Economy of Nature, and the Wisdom and Power of its Author. Vols. I. and II. 12mo. London; Whittaker, Treacher, and Co.; 1830.

We take shame to ourselves for having so long neglected to notice this interesting little work, the first volume of which has been lying on our table, unheeded, we blush to say, for more than a year and a half! We can assure the author we intended no disrespect to him by this delay; a delay, indeed, which we the less regret, as it enables us to "kill two birds with one stone;" or, in other words, to introduce our readers to the second volume also, which we have now received. Tardily, however, as we have at last entered on the task, we must content ourselves even now with taking but a slight and hasty glimpse at the work before us. Our limits would absolutely forbid us from following our author step by step in all his rambles

"O'er moss and moor, by mountain and by flood;"

and, besides, our wish is, to prevail on our readers to go to the book itself, rather than allow them to put up with what at best must necessarily be but an imperfect and garbled account of its multifarious contents. Works on natural history, both of the scientific and the popular cast, calculated respectively for the use of the learned few and of the unlearned many, have abounded in the present day; and the circumstance may be regarded as at once both a proof of the increasing taste for the study of nature, and in great measure as the promoting cause of such increase. Without drawing invidious comparisons between the respective merits of these two distinct classes of literary productions, or praising one at the expense of the other, suffice it to say, once for all, that we think each very good and very useful in its way. "I admit," VOL. V. No. 23.

E

says the writer, in his preface," the merit of the systems and subdivisions: for those who devote themselves to a single science, they are admirable; but to the great body of the people they are worse than useless." So far from decrying scientific works, we take the greatest delight in them; yet at the same time we profess ourselves admirers of the Selborne school. Wishing to see a love of nature become more general and diffused, and convinced as we are "how delightful and how profitable it would be, if all would be their own naturalists, and go to the living fountain instead of the stagnant pool," we hail with satisfaction the appearance of any work which has a tendency to create and foster a taste for natural history in these kingdoms. Just such a work is the British Naturalist. Addressed, as it were, " ad populum," and put forth in a form intelligible to all, the book can hardly fail of attracting the favourable attention of the public, and obtaining a very extensive circulation. We are pleased also with the general tone of good feeling which pervades the whole. In the introductory chapter, which contains many excellent and judicious remarks, the student is directed to the proper end and object of his studies in the field of nature, the knowledge and adoration of God. We extract the concluding paragraph of this portion of the work:

"The only sure way to become naturalists, in the most pleasing sense of the term, is, to observe the habits of the plants and animals that we see around us, not so much with a view of finding out what is uncommon, as of being well acquainted with that which is of every-day occurrence. Nor is this a task of difficulty, or one of dull routine. Every change of eleva tion or exposure is accompanied by a variation both in plants and in animals; and every season and week, nay, almost every day, brings something new; so that, while the book of nature is more accessible and more easily read than the books of the library, it is at the same time more varied. In whatever place, or at whatever time, one may be disposed to take a walk ; in the most sublime scenes, or on the bleakest wastes; on arid downs, or by the margins of rivers or lakes; inland, or by the sea-shore; in the wild or on the cultivated ground; and in all kinds of weather and all seasons of the year; nature is open to our enquiry. The sky over us, the earth beneath our feet, the scenery around, the animals that gambol in the open spaces, those that hide themselves in coverts, the birds that twitter on the wing, sing in the grove, ride upon the wave, or float along the sky, with the fishes that tenant the waters, the insects that make the summer air alive; all that God has made, is to us for knowledge, and pleasure, and usefulness, and health; and when we have studied and known the wonders of His workmanship, we have made one important step toward the adoration of His omnipotence, and obedience to His will." (p. 38, 39.)

After the introduction, which we recommend to the attentive perusal of our readers, the subject matter of the remaining portion of the first volume is distributed into six heads, or chapters, under the respective titles of the Mountain, the Lake,