BOTANY. 



table ' 8. Above the line of perpetual snow, the oolil is 



iul'try occa ionally so much diminished, that a few plantj 



V 1 ' of KaniiH'.-iiliix "luciulis, and other similar uiiet., may 



new and tlu-ii !><- touml, in tin- clefts of some dark 



ruck using through the snow. Tins lui|>jn MS even 



to the height ot 5(K) feel above that line. Farther up 



the snow is very rarely moistened. Y< t some umbi- 



ii-d Lichens (((i/rop/uinr), &c. still occur in the 



crevices of perpendicular rocks, even to the height of 



2000 feet above the line of perpetual snow. Thei-e 



are the utmost limits of all vegetation, where the 



mean temperature seems to be +1.1 of Celsius (.'50 



of Fahrenheit.) The snow bunting ( Km/ieriza ni- 



i'(ili.i) s the only living being that visits this elevated 



spot." 



The subjects of this Part of the article will be 

 found discussed in detail in the following works : 



Mr Knight's Papers in the PliiloM>plm-<il Tran.iac. Vegetable 

 lions for the 1HOO, 1MH, ISO.', 1M>.!, INOV, ISOj, ''"; 

 lSO*i, I.S07, 1SOH, ISO)), 1S10. Mr Knight's Papers ' 

 in the First and Second Parts of tiie Transactions of 

 t/ie Horticultural Society, Mrs IbNpim'-. Papers in 

 Nicholson's Journal. Smith's Introduction to Bo- 

 tuny. Willdenow's Iiitnidnctinn to liotini/. Kxxii 

 de Physiologic f'cgft'ile, p.ir Gerardm. 'J'raile 

 d' Anatomic el dc I'lu/sio/i.^ic, fegelales, par Mirbel. 

 Trailc .s/ir lex Arbres, par Duhamd. Crew's Ana- 

 tomy of Plants. Liontei Philosophia Botanica. I,up- 

 Idiid Tour of Linnaeus, by Smith. Phytiologie re- 

 getii/e, par Sennebier. Itccherc/ics Pkt/siologiqlief, 

 par T. De Saussure. Darwin's Phylologia. Thorn. 

 son's Chemistry. Ellis' Inquiry into the Changes 

 produced in Germination, Fegetation and Respira- 

 tion, Parts 1st and 2d. 



PART III. CLASSIFICATION. 



IT is very evident, that, without some arrangement, 

 the mind of man would be unequal to the task of 

 acquiring even an imperfect knowledge o f the va- 

 rious objects of Nature. Accordingly, in every 

 science, attempts have been made to classify the dif- 

 ferent objects that it embraces, and these attempts 

 have been founded on various principles. Some have 

 adopted artificial characters ; others have endeavour- 

 ed to detect the natural relations of the beings to be 

 arranged, and thus to ascertain a connexion by 

 which the whole may be associated. These attempts 

 have been probably carried as far in botany as cir- 

 cumstances can permit ; and the success attending 

 them has been singularly striking. Linnaeus has 

 given the most beautiful artificial system that has 

 ever been bestowed by genius on mankind ; and Jus- 

 sieu has, with unrivalled ability, exhibited the natu- 

 ral affinities of the vegetable kingdom. In the sub- 

 sequent Chapters we shall present a concise account 

 of both, as well as of the natural method proposed 

 by Linnaeus. Every system must be divided into clas- 

 ses, which again must be subdivided into orders, ge- 

 nera, species, and varieties. A class is distinguished 

 by some character which is common to many plants ; 

 an order is distinguished by having some character 

 limited to a few plants belonging to a class ; a still 

 more limited coincidence constitutes a genus ; and each 

 individual of a genus is called a species, which con- 

 tinues unchanged when raised from seed. A variety 

 is formed by an accidental deviation from the specific 

 character, and easily returns by seed to the particular 

 species fr> m which it arose. The Essential character 

 of a genus is a short description of it, which contains 

 only the character which essentially distinguishes it 

 from every other genus. The Factitious character, 

 which, as Dr Smith observes, can never stand alone, 

 is an essential character, but where the number of 

 parts not of essential importance are included. All 

 these points are admirably discussed by Linnaeus in 

 his Philosophica Botanica. 



CHAP. I. 



ARTIFICIAL SVSTEM OF LIXN.F.CS. 



THE system of Linnseus, now universally adopted Artificial 

 by scientific botanists, is professedly artificial : it com- System of 

 bines perspicuity and elegance in an uncommon de- 

 gree, and it may, indeed, be considered the most per- 

 fect arrangement that has ever been conceived by the 

 mind of man. This system has for its basis the di- 

 versity which prevails among the reproductive organs 

 of plants, which are, as we have already shewn, (Part 

 II. Sect. 6.) the stamens and the pistils; the for- 

 mer being considered the male organs, and the latter 

 the female organs. In some plants these parts are 

 distinctly visible ; in others they cannot be perceived; 

 and on this distinction the great division is founded. 



SECT. I. Classes.* 



LINNJEUS' system is composed of 24^ classes ; Classes, 

 of these 23 are distinguished by the number, situa- 

 tion, proportion, or connexion of the stamens. The 

 orders are founded on the peculiarities of the pistil, 

 or some other equally obvious circumstance. Each 

 order is again divided into Genera, and each Genus 

 into Species and Varieties. The first eleven Classes 

 are distinguished entirely by the number of the sta- 

 mens, and are as follows : 



1. MONANDRIA. Stamen 1. Examples, Salicornia, 

 Blitum. Plate Ixxii. 



2. DIANDRIA. Stam. 2. Ex. Jasminwn, Antfiox- 

 anthitm. 



3. TRIANDRIA. Stam. 3. Ex. Iris, Hordeum, 

 Holosieum. 



4. TETHANDRIA. Stam. 4. Ex. Scabinsa, Cuscufa. 



5. PENTAND.-IA. Stam. 5. Ex. 3'u<.s<itis. 8ui.<ola, 

 Sambiicii-i, Parnaxsia, Slat ice, Myostorttt. PI, Ixxii. 



6. HEXANDRIA. Stam. 6. Ex. Narcissus, Ory- 

 za, Kiimex, Wendlandia, Lilium. Plate Ixxii. 



In the rigorous use of terms, system is confined exclusively to any arrangement which is founded, throughout all It* 

 parts, on some O'ic principle; while muthod iji an arrangement less fixed and determinate, and some deviations may be made 

 without violating the general principle of such an arrangement. It is evident, from these definitions, that no perfect systtTa 

 has ever been, or prohably ever can be contrived; we must therefore be satisfied with an approximation to perfection; and 

 such an approximation Linnaeus' artificial, or, as it is sometimes called, sexual system, may be safely considered. 



VOL. IV. PAKX I. K 



