the bark of Thespesia (Hibiscus) populnea (Portia tree) are employed by native practitioners for the cure of cutaneous diseases. An infusion of the roots of Pavonia odorata is prescribed as a diet-drink in fevers. Other species of this order are, and nearly all from their mucilaginous properties, may be, similarly employed. The petals of Hibiscus Rosa Sinesis (Shoe-flower or China-rose) communicate, when rubbed on paper, a bluish purple tint which forms a very excellent substitute for Litmus paper as a chymical test. It has been already remarked that the fibres of the bark of Hibiscus Cannabinus are employed in the formation of course cordage, those of most of the larger kinds might be thus used, as in all they are very strong. The heart wood of Thespesia (Hibiscus) populnea is dark coloured and very hard, somewhat resembling that of the chesnut, and like it, adapted for the formation of gun stocks and similar purposes requiring a hard close grained, but not heavy or large sized, timber, which this rarely becomes, owing to the white outside portion being like that procured from all the other arborious forms occurring in the order, soft and of little value.
This last named species enjoys in a remarkable degree, a peculiar tenacity of life, large branches, after being severed from the trunk, surviving long enough to admit of their taking root, when planted as cuttings, like slender slips, and in a few months presenting the appearance of very respectable sized trees. It is worthy of remark however, that the trees so produced, rarely produce seed though they flower freely, and what is perhaps not less deserving of notice, they all decay in the centre, hence it is now rare among them to meet with either the mature fruit, or a sound timber tree, the practice of thus propagating them by cuttings, in place of by seed, for so long a time, having at length apparently destroyed their reproductive power, and deteriorated the quality of their vegetation.
But it is in their last mentioned capacity, that of affording clothing, that the Malvaceae become the greatest benefactors of mankind, Cotton being the produce of a genus of plants appertaining to this order. The genus Gosst/pimn from which it is derived, embraces but few species, and these of difficult discrimination, owing to long culture having caused them to run into every variety of form. So great indeed is their tendency to run into variations that some Botanists have even doubted whether there are more than two distinct, and permanently distinguishable species, among the whole host of forms that have by different authors been supposed entitled to rank as such.
To some it may appear a question of little moment whether we consider all these forms as species or varieties so long as they continue permanent. This is partly true, but at the same time it is desirable to ascertain what are species and what varieties, since the term species implies permanency, while variety conveys exactly the opposite idea, or that of liability to change under any variation of the circumstances under which they may be produced, hence their aptitude for culture unchanged in some favoured situations and their disposition to change in others to all appearance equally favourable. My own observations certainly lead me to adopt the conclusion, that the species have been unnecessarily multiplied by some, and reduced too low by others. Thus DeCandolle enumerates 13 species, and Mr. Royle eight, both these catalogues will probably be found in excess. Dr. Lush and Jacquemont reduce them to two. These Botanists probably err in the opposite extreme, but yet, as their opportunities of observation were great, their statements must be received with deference. They seem to attach no value to characters taken either from the colour or quality of the wool on the seed, or the absence or presence of a coating of short hair or down, with which the seed of some sorts are clothed ; neither to the forms of the foliage or native country, or clothing, or habit, of the plants, whether glabrous or hairy, arborious or annual. According to this view the various Indian forms in which a somewhat palmate form of the foliage prevails and is most constant, and the American ones figured here under the specific name of G. barbadense , in which a lobed and angled foliage is equally permanent are all mere varieties of the same plant, while the form named G. acuminatum is, on account of its adherent seed alone, looked upon as a distinct species. With this view I confess I feel disposed to coincide to a great extent, though not to go the whole length, since I cannot yet bring myself to acknowledge the specific identity of the constantly palmated leaved and hispid Indian forms, and the equally permanently lobed and angled leaved and glabrous American forms. The more so, as these forms retain their peculiarities of foliage in all the varied situations and circumstances in which they have been made to grow in all the four quarters of the world. Under this view, I acknowledge three species as cer-
