PLANTS. 211 



instance, the organs of multiplication are very evident, 

 as they are in nearly all the phsenogamous or flowering 

 plants. The pistil occupies the middle of the corolla, at 

 the termination of the axis. It consists of three parts : 

 the ovary, or germ, the style, and the stigma, and around 

 it are six stamens. Above these are little round bodies 

 or sacs, containing a fine dust, which is the fructifying 

 pollen. Thus, from their peculiar structure, the flowers 

 belonging to this class, termed polygamia or unisexual, 

 contain the procreative principle within themselves ; and 

 even as this is the case in all the Lilyacese, so there are 

 others, like the hemp, in which some plants only are the 

 seed-bearers, or in the pine, on which are found blos- 

 soms evidently different as to sex. Many plants, how- 

 ever,, are so small that the sexual characteristics can not 

 be determined. 



If the movement of the sap in a plant is in any way 

 interrupted, the parts immediately begin to wither and 

 decay, and it soon dies altogether. Many last only one 

 year, and, dying as soon as their seed is matured, are 

 called annuals ; others require two years before they 

 attain their ultimate perfection : these are termed bien- 

 nials ; and again, there are some, which, existing for an 

 indefinite number of years, are known as perennials. 



Linnaeus, whose system is considered the most simple, 

 distributed the plants into classes according to the num- 

 ber, size, growth, or peculiar functions of the stamens or 

 male organs. These are as follows :* 



* Some naturalists have based the arrangement on the texture and 

 size of plants, classing them in divisions of Herbs, Shrubs, and Trees. 

 Others, again, on the structure and form of the Calyx, the Corolla, 

 the Fruit, etc, or on the presence or absence of some important organ : 

 the favorite object, at present, following Jussieu and De Candolle, is 

 to arrange plants strictly according to their affinities ; to group to- 



