SYSTEMATIC BOTANY. 



Enneandria. 



Octandria. 



Decaudria. 



Polyandria. 



Icosandria. 



XXIII. POLYGAMIA. The class POLYGAMIA (a 

 word signifying many marriages) contains plants 

 having both unisexual and bisexual flowers on the 

 same or on different individuals. There is con- 

 siderable uncertainty about the arrangement of 

 this division, because some of the genera are not 

 always constant in their modes of flowering; and 

 even single plants will occasionally exhibit all the 

 characters by which the different orders are dis- 

 tinguished. Here are the mimosas, the acacias, 



Dioecia. 



the maples, the Ailantus, the mango, some palms, 

 the anacardium, and the figs. 



XXIV. CRYPTOGAMIA. The class CRYPTO- 

 GAMIA (a term signifying hidden marriages) con- 

 sists of the flowerless plants corresponding with 

 the class of the same name in the natural system. 

 It is illustrated by ferns, mosses, lichens, fungi, 

 and sea-weeds. 



THE NATURAL SYSTEM. 



' The Natural System of Botany,' says Dr Lind- 

 ley, ' being founded on these principles that all 

 points of resemblance between the various parts, 

 properties, and qualities of plants shall be taken 

 into consideration; that thence an arrangement 

 shall be deduced in which plants must be placed 

 next each other which have the greatest degree of 

 similarity in these respects ; and that consequently 

 the quality of an imperfectly known plant may be 

 judged of by that of another which is well known 

 it must be obvious that such a method possesses 

 great superiority over artificial systems, like that 

 of Linnaeus, in which there is no combination of 

 ideas, but which are mere collections of isolated 

 facts, having no distinct relation to each other. 

 The advantages of the Natural System, in applying 

 botany to useful purposes, are immense, especially 

 to medical men, who depend so much upon the 



Monadelphia. 



vegetable kingdom for their remedial agents. A 

 knowledge of the properties of one plant enables 

 the practitioner to judge scientifically of the quali- 

 ties of other plants naturally allied to it; and 

 therefore the physician acquainted with the natural 

 system of botany may direct his inquiries, when 

 on foreign stations, not empirically, but upon fixed 

 principles, into the qualities of the medicinal plants 

 which have been provided in every region for the 

 alleviation of the maladies peculiar to it He is 

 thus enabled to read the hidden characters with 

 which Nature has labelled all the hosts of species 

 which spring from her teeming bosom. Every one 

 of these bears inscribed upon it the uses to which 

 it may be applied, the dangers to be apprehended 

 from it, or the virtues with which it has been en- 

 dowed. The language in which they are written 

 is not indeed human: it is in the living hiero- 

 glyphics of the Almighty, which the skill of man is 

 permitted to interpret. The key to their meaning 

 lies enveloped in the folds of the natural system, 

 and is to be found in no other place.' Such a 

 system as is here eloquently delineated, we aim at 

 rather than possess. All the modifications and 

 they are neither few nor unimportant of Jussieu's 

 original plan which have been promulgated, are 

 merely contributions to one great end ; and years 

 of patient research, crowned by the most extensive 

 powers of generalisation, must elapse before botany 

 can boast of a perfect system. 



According to the original system of Jussieu, all 

 the known plants were arranged into a hundred 

 Orders, beginning with the Fungi, and mounting 

 upwards to the Coniferce; and these Orders were 

 divided into three great Classes namely, the 

 ACOTYLEDONES, or plants without any cotyledon or 

 seed-lobe; the MONOCOTYLEDONES, plants with one 

 cotyledon; and the DICOTYLEDONES, those with 

 two or more cotyledons. The Acotylcdonous plants 

 were not subdivided ; but the Monocotyledones 

 were arranged into sub-classes, according as the 

 stamens were hypogynous, or arising from under 

 the pistil ; perigynous, or growing from the calyx ; 

 and epigynous, or arising apparently from above 

 the ovary by adhesion to it. The Dicotyledones 

 were divided into the apetalous, or those without 

 petals; the monopetalous, those with one petal; 

 and the polypetalous, those with several sepa~ ' 



87 



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