studied, the organs of reproduction were better examined and due attention was paid to the essential products of vegetation-the fruit and seed. In consequence, the science made rapid advances and resulted in the construction of a natural method and arrangement of plants. France, Germany and Italy vied with each other in discoveries. The botanist of the present day is familiar with the names of Lorentzo Jussieu, Augustus Pyramus Decandolle, Mirbel, Rudolphi and Treviranus, whose works on structural botany and natural systems were published at the beginning of the present century. Since that period, botany has made rapid strides The natural systems of Jussieu and Decandolle have been materially improved by Endlicher, and more especially by Lindley in his elaborate work entitled "The Vegetable Kingdom." The various interesting researches of Gaudichaud, Schleiden, Mohl, Brown, Amici, Griffith, Schultz and others, have in a measure completed our knowledge of the structure and functions of the different parts and organs of plants and of their alliances and affinities; while the labours of Liebig, Mülder and Johnston on the chemistry of plants have tended to the application of botanical science to the interests of agriculture and horticulture, at the same time that others as Christison, Royle, Burnett and Lindley, have supplied valuable data in reference to their medicinal properties and diatetic uses. Not less important and interesting have been the researches and observations, both practical and speculative, made in reference to the geographical distribution of plants over the globe as well as regarding those plants which existed on the earth in its primæval state and which now lie as monuments of vanished forms of vegetable life, buried in the vast geological epochs that elapsed before the establishment of the present order of things.

And what has been the ultimate effect of this? Why, it has raised the standard of botany to the high rank it should hold— rivalling, if not excelling its sister sciences-and has established it within schools and universities as one of the most interesting, beautiful and useful of studies. It claims as its votaries a host of the most accomplished of minds and of the highest order of rank, and it now flourishes in all countries and in every clime. And why should Canada rest satisfied-now that she is interesting herself in the subject of schools and colleges-till she has established these as nurseries of science as well as of arts and literature-nurseries that will rear up ;ouths of talent and ability, to be hereafter claimed as lasting monuments of honor and credit to the country.

You will perceive, from the short sketch just given you, that the tendency of scientific investigations, has been to reduce to practical and useful ends the knowledge acquired by research, and that the spirit of enquiry, however exclusively scientific, has generally subserved in some way one or more of the special interests of man. It will be my anxious desire, in the present course of lectures, to give you a faithful representation of botanical science in its present advanced state, and place prominently before you such important facts and considerations as bear specially on medicine, agriculture and horticulture. I have no doubt you will ere long become interested in the subject and it will give me pleasure to furnish you with such information as you may occasionally require, and such facilities for the prosecution of the study as may be within my power. The deeper your study of the operations and phenomena of nature, the more intimate your acquaintance with the structures and functions of the plant, the greater will be the pleasure and gratification you will experience and the more profound will be your admiration of this portion of God's creation. With a knowledge of botanical science, you cannot but take delight hereafter in the contemplation of those beautiful and varied objects of nature that will constantly meet your eye, and if you study them as living organizations as well as the manifestations of life they exhibit and the laws which govern them-if you study such phenomena in the true spirit of wisdom, they will subserve a better and higher purpose than the mere gratification of the mind. They will enrich it with pure and lofty thoughts and raise your souls in admiring contemplation of Him, at whose fiat, at the beginning, "the earth brought forth grass, the herb yielding seed after his kind, and the tree yielding fruit, whose seed was in itself, after hist kind," and can we ignore the beauty and perfection of the plant, when it is recorded in the same breath, that "God saw that it was good."

ARTICLE XXXI.-Description of four species of Canadian But

Palpi, short, cylindrical, moderately compressed, three jointed, the last joint as long or longer than the preceding; antennæ long

and slender, terminated by a somewhat abrupt, compressed, obtuse club, consisting of seven or eight joints, and grooved on one side; wings opaque, and thickly clothed with scales; anterior pair nearly three-cornered, the apical angle not very acute; posterior pair rounded, partly embracing the abdomen, and the discoidal cell closed; legs long, slender, and alike in both sexes, the anterior pair being perfect; tarsi terminated by two equal sized hooklets much curved, each having a small tooth on its under side; between these hooklets is along fleshy cushion, and each is laterally defended by a long conical hirsute appendage; eyes naked; head rather small. Larvæ cylindric,elongated and fleshy, with numerous points or larger tubercles, which emit pale hairs, and are arranged in regular transverse series; the head small and rounded. Pupa angulated, with a short process in front of the head, and with a projecting lateral appendage behind each of the wing cases, they are attached by a tuft of silk at the tail, and a loose girth round the middle of the body. They do not constantly place themselves in one position with the head upright, but undergo this state in various positions.

This genus is very extensive, the species being distributed over most parts of the globe, but especially in the intertropical parts of the old world, the western hemisphere being comparatively poor in species. The prevaling colour is white, more or less pure, with a black border to the anterior wings, variable in width but seldom wanting. Some of the exotic species are much more varied in their colouring, The underside of the posterior wings generally differs considerably from the upper, and is often very agreeably varied with brilliant colours. The sexual differences in certain species are very conspicuous but in others much less so, the females being distinguished from the males only by a somewhat broader band, or by having the upper wings more rounded at the apex. Such of the larvæ as are known feed almost exclusively on the Cruciferæ, especially the species of Brassica, as well as on the Residacea Tropeolia and Capparidea. In some years certain of the common English species abound to an astonishing extent, and at such times the cabbages and other cruciferæ in gardens, almost disappear under their attacks. It is nearly the only genus of Diurnal Lepidoptera injurious to man and to keep them in check Providence has provided several small species of hymenopterous parasites, (microgaster glomeratus, &c,,) which live within the body of the caterpillar till the latter is about to assume the pupa state,