xx 
which may therefore be supposed to have descended from a single 
individual. 
. Species are perhaps the only truly natural divisions of plants; 
but naturalists, for convenience of reference and description, have 
been compelled to arrange them in more or less artificial groups or 
families. Certain plants possessing a great resemblance to each 
other in structure are formed into genera; these are collected into 
larger groups called orders, and the orders into subclasses and 
classes. All these divisions are dependent upon some general 
similarity in the structure of the plants composing them, usually 
in that of the flower and seed, those organs being less liable to 
variation than others. Linnzeus, the founder of modern systematic 
Natural History, adopted the number and position of the stamens 
and pistils as the basis of his classification of the flowering plants, 
forming the names of most of his classes by affixing the word 
andria, the synonym of stamen, to the Greek numeral expressing 
the number of those organs present in the flower: thus plants, 
the flowers of which contained but one stamen, were called Mon- 
andria; those having two, Diandria. The orders or subdivisions 
of these were formed in a similar way by adding the word gymia, 
adopted as synonymous with pistil, tothe numeral. Other divisions 
he made dependent upon the connexion of the filaments or anthers, 
and the moncecious or dicecious character of the plant. We have 
not space to enter mto the details of his system, and have only 
made allusion to it because it has been adopted in the ‘ English 
Botany’ and some other works of reference still in use. Its sim- 
plicity rendered it of easy application by the unscientific ; but it had 
the great disadvantage of bringing together plants of widely different 
affinities into the same artificial section, owing to some coincidence 
m the development of a single organ, while it separated others 
evidently closely connected ; it is therefore no longer used by natu- 
ralists, and the mode of classification adopted by Jussieu and De- 
Candolle, variously modified by other botanists, has been substituted. 
