a natural system, which he declared to be, Primum et ultimum in botanicis desideratum.'

Twenty years ago, however, this artificial system of Linnæus was the one universally adopted by botanists in this country; now, this once popular system is declared by our author to be a "matter of history merely;' and the merit of the substitution of a more scientific arrangement, upon a natural system, in this country, is claimed with justice by Dr. Lindley as belonging to himself.

6

The natural system, which has displaced the one of which we have spoken, is described as being that which is founded on the principle that all points of resemblance between the various parts, properties, and qualities of plants shall be taken into con'sideration; that thence an arrangement shall be deduced in ' which plants must be placed next to each other, which have the 'greatest degree of similarity in those respects.'

The advantages of this system over the other are of a decidedly practical nature, and not merely theoretical or scientific. Upon this plan, a knowledge of the properties of one plant enables the botanist to judge scientifically of the qualities of other plants naturally allied to it; so that the physician, acquainted with 'the natural system of botany, may direct his inquiries when on foreign stations, not empirically, but on fixed principles, into the qualities of the medicinal plants which have been pro'vided in every region for the alleviation of the maladies pecu'liar to it.' Though Dr. Lindley has thus chosen his illustration of the practical utility of this system from the advantages which it may afford to the more enterprising members of the medical profession, yet, obviously, it is capable of much more general application; the poisonous nature of an unknown species, or its harmless and nutritious properties, may, by this method, be at once declared to the scientific colonist or the traveller, as well as its probable value for any of the economic purposes to which civilization applies the varied productions of the vegetable kingdom. With respect to its scientific value, we before alluded to the help which this system gives to the farther illustration of the real structure or function of parts which may otherwise seem anomalous or unintelligible; by comparing a plant which may present such difficulties, in any of its parts, with other plants, between which and itself close affinities do evidently exist, the true analogies of the questionable organ may often at once declare themselves. Again, by forming an arrangement of the entire known vegetable kingdom in genera, orders, and classes, according to the natural affinities and true relations of their species with each other, we are conscious of a new pleasure in

acquiring clearer and more enlarged views of the connexion which exists throughout the organic world, and of the harmony which pervades the works of nature; we see how almost insensible are the gradations of development between the lowest and most insignificant instance of vegetable life, and its most noble representatives-between the green slime upon a a moist pavement and the majestic timber trees of the forest; and we no longer regard each specific form as an isolated fact, but as forming an integral part of one comprehensive and well-ordered scheme, embracing the varied works of nature throughout the most distant countries and the most opposite climates.

At the present day,-when the research of botanists has made us acquainted with such numerous and diversified forms of vege tation in all parts of our globe, so that upwards of 80,000 existing species are at present known and described; and when not merely recent plants are brought under observation, but the fossil remains of species which have passed away for ages, are disentombed from their long burial in the strata, and exactly classified, the difficulties which present themselves in the exposition of such a scheme are very different from those which would have occurred at an earlier period, when our acquaintance with species was much more limited and less exact. Then the forma tion of such an arrangement in regular progression, and the subdivision of the whole into definite groups, would appear a work of no doubtful practicability, the true principles being once established, and only to require a more extensive knowledge of species for its complete accomplishment. The groups thus formed would many of them appear distinctly limited, though not, perhaps, advancing always with a uniform progression; gaps, or intervals here and there presenting themselves, the occupants for which, it would be fair to conclude, a more extended knowledge would subsequently supply. Now, this increase of knowledge is obtained with more than anticipated profusion, but the systematist does not find his difficulties removed, only their nature is somewhat altered; the negative of deficiency has passed the equilibrium, and has reacted into as embarrassing an excess.

It is true that many a hiatus has been appropriately filled up; but at the same time, the distinct limits between many of the groups have gradually disappeared, and the regular progres sion from forms of lower to those of higher development now appears diverted by many a flexure and ramification from a direct course. If we consider only the primary colours in the solar spectrum, the red, the yellow, and the blue are clearly distinct; but a nicer observation shows the intermediate tints by which

the colours so delicately coalesce, that we find it quite impossible to mark out, by exact limitations, the shades peculiar to each.

'No absolute limits, in fact, exist, by which groups of plants can be circumscribed. They pass into each other by insensible gradations, and every group has apparently some species which assumes the structure of some other group.' It is generally admitted by those who have considered the manner in which organized beings are related to each other, that each species is allied to others in different degrees, and that such relationship is best expressed by rays (called affinities) proceeding from a common centre (the species.) In like manner, in studying the mutual relationship of the several parts of the vegetable kingdom, the same form of distribution constantly forces itself upon the mind; genera and orders being found to be apparently the centres of spheres, whose surface is only determined by the points where the last traces of affinity disappear. But although the mind may conceive such a distribution of organized beings, it is impossible that it should be so presented to the eye, and all attempts at effecting that object must of necessity fail. If, in presenting the surface of a sphere to the eye at one glance, we are compelled to project it upon a plane, the effect of which is to separate to the greatest distance some objects which naturally touch each other, how much more impossible must it be to follow the juxtaposition of matter in treating of the solid contents of a sphere.'

It is thus that, even with the most natural system, much that is artificial co-exists; nature allows not the precise limitations by which the groups in a system must be defined; and she presents affinities between these groups much more numerous than can be shown in a table.

But granting that these smaller groups must prove incapable of exact definition, surely the boundaries maintain their integrity between the classes or primary divisions, into which has been apportioned the entire kingdom of Vegetabilia. Even these boundaries fade away and become invisible; Acrogens, and Endogens, and Exogens, are found each to be united by intermediate forms; our provinces, we find, are divided by no natural landmarks, and we are reduced to content ourselves with that precise demarcation by which we cannot doubt the botanist's own empire, the vegetable kingdom, is divided from the adjacent empire of animated beings. Here again we find ourselves at fault. The gradations between men and trees are quite insensible. No such thing as a definition exists in natural history. The difficulty has been felt from the time when Plato defined a man as a biped without feathers, and it is now greater than ever. 'It has been long asserted by Bory de St. Vincent, that there 'exist in nature organized bodies, which are animal at one period

' of their lives and vegetable at another. This, if true, would for "ever put an end to the possibility of distinguishing the two kingdoms, when they shall each have arrived at their lowest • forms.'

To some of our readers, such a doctrine may appear worthy of a place in classic fable rather than in modern science. It may seem to them as credible as that groves of oak trees whispered the Dodonæan oracles, or that Baucis and Philemon sprouted into arborescent ramifications, or that Polydorus was changed into a myrtle tree. But we would urge no opinions in science upon the authority merely of the poet's wonders. Neither can some later marvels, which have been set forth with somewhat more pretension, to be received as facts, be adduced at the present day in support of the conclusion at which our author has arrived; we are sceptical, for instance, as to the

'Shrieks of mandrakes torn out of the earth,

That living mortals hearing them run mad;'

and we are unable to accredit the wonders of the Vegetable Lamb of Tartary, though they might have formed an apt illus tration, had they existed elsewhere than in the brain of Struys the traveller, who, having inverted the thick, creeping, woolly stem of a fern, and made it stand upon four branches which he left for legs, produced an object, which, as improved by the artist's imagination, presented in the drawing a distant resem blance to some monstrous quadruped. This he called the Baro metz or Tartarian Lamb; and finding its mass to be somewhat fleshy, and to contain a pinkish sap, he thence contrived a precise and circumstantial account of a strange plant-animal; telling us that its woolly skin was worn by sailors as an under-waistcoat, that wolves preyed upon its tender flesh,-and that itself cropped the herbage around for food, and pined away when all was consumed. Darwin, in his Botanic Garden, equally imaginative, though claiming no exact belief for his poetic figures, thus presents the imaginary marvel in the form of verse:

Cradled in snow and fanned by arctic air,
Shines, gentle Barometz! thy golden hair;
Rooted in earth each cloven hoof descends,
And round and round her flexile neck she bends;
Crops the gray coral moss, and hoary thyme,
Or laps with rosy tongue the melting rime.
Eyes with mute tenderness her distant dam,
Or seems to bleat-a Vegetable Lamb.'

As we are neither poets, nor magicians, nor wonder-loving travellers, but merely honest reviewers, we cannot seek to corroborate a position upon such grounds as these. There are

indeed instances in which animal and vegetable natures seem to be curiously blended, and which are strictly veracious, but still not available for our purpose; such are those curious instances in which vegetable structures become developed on living animal tissues. The Muscardine is the name given to a disease by which silkworms are liable to be attacked in Italy and the South of France, which is ascertained to be owing to a minute fungus, a species of Botrytes, which forms in the interior of their body, and which proves infectious by the dissemination of the extremely minute spores or reproductive bodies of these microscopic vegetables. Gold fish are subject to a cutaneous disease, in the form of a white efflorescence, which may cause their death; this is a microscopic vegetable parasite, consisting of minute articulated tubes. Even in our own species, there are certain cutaneous and visceral diseases, which are proved to be owing to the lodgment and growth of minute vegetable parasites. But the most curious instances of this kind are those in which parasitic fungi attack the bodies of winged insects whilst as yet in their larva state, striking their fibres firmly in this living soil, and shooting out vegetations of a considerable size. Still the insects continue to live and pass through their metamorphoses, till developed into the image and furnished with wings, when they may be seen flying heavily through the air charged with their vegetable burdens. Representations of a caterpillar, thus encumbered with a fungous growth—a species of Sphæria, are given by Dr. Lindley on page 40; and a species of wasp in the West Indies may be seen flying with plants of their own length projecting from their bodies. Though somewhat more credible and much more veracious, such instances may remind us of the horse of Baron Munchausen, upon whose back he cultivated a branching tree, which afforded him a pleasant shelter as he rode along in pursuit of his rare adventures. But since these are not instances in point, let us see of what nature the facts really are which have led to the conclusion, that the animal and vegetable kingdoms can be distinguished by no certain boundaries.

Inasmuch as animals are confessedly beings of a higher organization, and endowed with more varied powers than are mere vegetable structures, it would seem a natural supposition that the nearest approximations of animal and vegetable forms would occur between the most elevated of the latter, and those of the former which possess the lowest organization and most imperfect development. This, however, is far from being the fact; forest trees, which may be taken as representatives of the higher forms of vegetation, resemble no animal beings, and cannot for a moment be mistaken for anything but what they really