putably the best part of the work now before us. The following extract is a fair specimen of his manner, and contains atter which will be generally useful, but. is not generally known.

"The caterpillar of one of the hymenop terous insects requently intests gooseberry £nd currant bushes, feeding on the leaves and destroying the health of the bushes; which not ozly bear no fruit the same year, but are considerably injured for a year or two folLwing. When you perceive your bushes to be deficient in leaves, you will, on examination, find them to have been eaten by this or some other caterpillar; and if they have been the most destroyed at the bottom of the bush, and nothing in general but the ribs and stalks of the leave, reinain, you may be assured that the mischief has been done by the insect, which I am now about to describe.

"The P rfect insect is a four-winged fly, rather larger than the common house-fly, word so,ae yellow upon its body, and much more sluggish in its motions. It is of the genus tenttired), one peculiarity of which is, that their antennæ or horns have a constant tremulous motion. These circumstances are suflicicat to distinguish the insect in its fly

state.

"In spring, as soon as the young leaves appear, thy bursts from the chrysalis, in which state it had lain buried in the earth all winter near the root of the bush. It creeps, but seldom flies, about the branches at the bottom of the bush, and soon finding a mate, the female deposits her eggs in rows along the ribs of the leaves on their under surface. In a few days the parents die. The young caterpillars are in a short time hatched, and begin their depredations by eating small holes like pin-holes on the leaves, where they are born. When the first leaf is devoured they march to another, and so on; but for many days they keep in company, some scores perhaps on the same leaf. When increased in size they separate, and feed singly, but never leave the bottom of the bush, till most of the leaves there are gone; they then travel gradually upwards, and always stick on the under surface of the leaves, by which they more effectually avoid becoming the prey of birds; added to which, their colour also, which is green, must preserve them in a great measure from such enemies. These caterpillars are distinguished from the caterpillars of butterfiles, and moths, by having as many as twenty feet, whereas the latter never have more than

sixteen. The hard covering of its head also seems one entire scale; whereas that of a lepidopterous caterpillar consists of two. nest of these insects will sometimes strip 3

One

whole bush of its leaves. When ful grown they retire to the earth, remain there in carysalis but a few days, and then a second bruûd more numerous than the first appears; tay deposit their eggs in the same manner, and destroy all the leaves on the summer shpats, The second brood appears in the fly stura about July, and the young fry is hatched in a week or ten days afterwards.

From an acquaintance with the natural history of this insect we discover the proper time and manner of searching for, and taking it; and the process is to simple, and so certain, that whoever allows a repetition of the injury, amply deserves it for his negligence.

"Where the bushes are known to have been intected the preceding summer, let them be daily attended to as soon as the spring leaves appear, and let every fly of the desciption above given be taken wherevez it can be found; the sluggishness of its motora makes it an easy prey; and be it remembered, that the destruction of every female, la fore it lays its eggs, is equal to the destruction of several hundred caterpillars. Let this search for the fly be repeated in July. Whenever at any season you discover your bushes to be infested with the caterpillar of this insect, which is known by the loss of leaves, pate cularly on the bottom branches, you must examine eaca bush separately, and seize your prey wherever you detect him. Nor is this so arduous a task as it may at first appear. One person may easily clear fifty bushes in a day; and surely the preservation of so muca fruit will amply repay for the trouble and expence, If the search is made early, before the young caterpillars are dispersed, the trouble will be very much abridged. Every leaf, that is partially eaten, must be plucked off by nipping the leaf-stalk with the thumb and finger, and it will seldom happen but one or more caterpillars will be found on its ucder surface. They must be carefully removed from the garden, or destroyed when taken. The search should be repeated a few times, lest any stragglers should have escaped, or any fresh caterpillars be hatched, as they do not all appear exactly together. Due aftention to this plan will effectually root qui the evil; and after one year's search few insects will be found for some succeeding years, so that a slight annual examination will preserve your bushes afterwards."

PP. 500,

IT would greatly facilitate the progress of the student, if, in every branch of science, there were one accurate and comprehensive elementary work, written in

$10.

a plain and easy style, and arranged in a natural and lucid order. Introductory treatises we have in abundance upon every subject; but comparatively few which are

the production of authors completely competent to the task. In the present ardent pursuit of botany in particular, through every part of Europe, and wherever Europeans reside or travel, no one has a right to complain that he cannot find a guide. The only difficulty is, to determine which is best qualified for the purpose. There is, indeed, one great original from which all draw the greatest part of their materols, and to which all look up as nearly decisive authority. The Philosophia Botuica of Linnæus possesses such pre-eminent excellence, that it would be presumption in any one to disclaim its assistance, and to attempt a similar composition entirely derived from other sources. The best works of the kind in the English language are little more than translations or abridgments of it, in connection with the Termini Botanici, and some other tricts published in the Amonitates Academic and the Delineatio Plante, prefixed to the vegetable part of the Systema Naturæ.

While science is, as it always must be, in a state of progress, even its first clements cannot be altogether stationary. A wider survey of the subject, and a knowledge of new particulars, will produce more accurate definitions, more clearly marked distinctions, and a better arrangement: this was experienced by Liunaus himself. The Philosophia Botanica, Termini Botanici, and Delineatio Plantæ, are not always consistent with each other; nor do his earlier and later practical works entirely correspond: but, since the time of his death, the field of botanical research has been wonderfully extended. The herbarium, the greenhouse, and the stove, have been enriched with new tribes of plants, many of which have a structure and habit almost as remote from those which were before known, as are the countries which gave them birth, from the nations of civilized Europe. The science, therefore, has in many respects assumed a new appearance, and, with respect to some of its parts, must be taught in a new foren.

This can be done only by those who have the means of becoming acquainted with all the recent acquisitions, and can view the whole with a scientific eye. The author of the work now before us is of this class. Professor Willdenow is not only in the regular habit of teaching the science, which we consider as nearly an absolute pre-requisite to the composition of a good elementary book: but having

been long employed in collecting and digesting materials for a new edition of the Species Plantarum, must have acquired a precision and facility in the use of terms, which can be the result only of long practice and much reflection. His introduction to botany, we are told, has accordinglysuperseded in Germany all others of the longest standing and greatest reputation." That it will meet with equal success in Great Britain is more than we will venture to predict; but we can pronounce it a valuable addition to those which we before possessed, and shall not, we trust, be suspected of a desire to disparage the publications of our own country, if we add that it contains a considerable quantity of matter which is not to be found even in the best of them. The latest author must be negligent indeed, if he do not secure to himself a right to boast of this advantage.

The work, after a general introduction, is divided into eight parts under the fol lowing titles: terminology, classification, botanical aphorisms,nomenclature of plants, physiology, di-cases of plants, history of plants, and history of the science.

In the terminology the professor has generally, but not always, adhered to the explanations given by Linnaeus, and has added most of the new terms which have been employed by subsequent authors. A capsule, for instance, according to him, is

a pericarp consisting of a thin coat which contains many seeds, often divided into cells, and assuming various forms." According to Linnæus, it is “a hollow pericarp opening (dehiscens) in a determinate manner:" a definition which does not exclude either the silique, the legume, or the follicle, though all these are made by him distinct kinds of pericarp. There is, indeed, in many of Linnæus's divisions, a want of logical exactness; and we have lately learnt, from his own account of himself, that, through the whole of his early studies, he was too much absorbed in the investigation of plants, to attend to several of the sciences which are taught in the Swedish universities as preparatory to a course of theology, of which logic is indisputably one. We will not deny that, in some points of view, he was much better employed; and that a sagacious attention to the face of nature did more for him than all the logic of his days could ever have done: but we must at the same time observe, that a general initiation into the rules of that art would have prevented a few improprieties into which he has

have I noted a single instance where this wise measure of nature was omitted. I examined purposely all those plants which were said to want the cotyledons, and always met with them. That in some plants the existence of the cotyledons was altogether denied, and others were said to have one only, others two, and several plants more than two, arose partly from inaccurate observation, partly from mistaking a part of the plumula for a cotyledon. Placenta or cotyledon is the name of the whole entire substance of the seed, not including the parts of the corcle. It arises in many plants with the plumule above ground, and is couverted into leaves, or it remains in the ground, and as in the gramina, the first leat of the plumule only rises, which is what some thought to be a cotyledon. In the flax and species of fir, both cotyledons are converted into leaves, and the leaves of the plumula are evolved immediately after them, and of the same magnitude and appearance. Hence it was that botanists supposed there were many cotyledons. The division, therefore, of plants in acotyledons, monocotyledons, dicotyledons, and polycotyledons is er

'roneous."

The diseases incident to plants are formally and minutely detailed, with, the best methods of cure as far as they are curable, but this part of the work, like the preceding, does not admit of abridgment.

dually emerged from the bosom of the deep. On this supposition he founds five principal Horas in Europe, which he calls the Northern, the Helvetic, the Austrian, the Pyrenean, and the Appeninian, and asserts that there is the most marked difference in the lists of plants which they severally produce. Observations of this kind are curious and worth pursuing; but great care should be taken that the imagination does not run away with the judg ment, and that facts be not forcibly distorted into an unnatural correspondence with a preconceived theory.

The germ of the eighth and last part may be found in the Bibliotheca Botanica of Linnæus, and in two tracts published in the Amoenitates Academicæ, entitled Incrementa Botanices and Auctores Botanici; but the whole is greatly enlarged, and brought down to the present time. In the second of these work; the history of botany is divided into our periods: the first includes all the ancient writers, and comes down to the restoration of literature, at the time when Constantinople was taken by the Turks; the second begins with Brunfels and ends with C. Bauhin; the third comes down to Linnæus; and the fourth is distinguished by the propagation of the sexual system. Professor Willdenow, with a more accurate observation of the great revolutions that have taken place in the science, divides it into eight. 1. From the origin of the science to Brunfels. 2. From Brunfels to Casalpinus, or from 1530 to 1583. 3. From Cæsalpinus to C. Bauhin, or from 1582 to 1593. 4. From C. Bauhin to Tournefort, or from 1593 to 1694. 5. From Tournefort to Vaillant, or from 1694 to 1717. 6. From Vaillant to Linnæus, or from 1717 to 1735. 7. From Linuæus to Hedwig, or from 1735 to 1782.. 8. To the present time, i. e. 1805. Without intending to derogate from the established reputation of Hedwig, we cannot help thinking that if our author had not conceived a prejudice against Jussieu, he would have fixed the commencement of his eighth period at the year 1789, when that great naturalist published his Genera Plantarum secundum Ordines naturales disposita. Under each period all the botanical writers are enumerated, with the titles and dates of their principal works. The lovers of botany would have been still more gratified if a complete list of their works with the different editions had been annexed. Such a list would not have taken up much more room; and as a syn