128 
NATURAL METHODS. 
been placed. We thus form natural families. If the whole vegeta- 
ble kingdom could thus be distributed into natural tribes, we should 
need no artificial system. But after selecting a few families, which 
exhibit striking marks of resemblance, we find genera whose re- 
lation to other genera seems doubtful or obscure, and at length find 
a vast number of plants which seem to have few natural affinities 
with any other. 
Among resemblances which gives rise to natural families, are, 
1st, resemblance in seeds, 
2d, in pericarps, or the envelopes of seeds, 
3d, in stamens and pistils, 
4th, in corollas and calyxes, 
5th, in the modes of infloresence, or the manner in which the 
flowers grow together upon the stalks, 
6th, in leaves, 
7th, in roots and stems. 
In order to form a correct idea of the natural methods of classifi- 
cation, it is necessary to observe many plants, and the most con- 
stant characters of their organs. To find the place of plants in the 
artificial classes and orders, it is only necessary to observe the dis- 
tinctions of the stamens and pistils. 
The physician is chiefly conversant with the natural characters of 
plants, especially with such as are connected by medicinal qualities; 
he considers one group as narcotics ; another as tonics ; another as 
stimulants^ &c. 
The natural method depends for its utility, much upon the artifi- 
cial system, which enables the student to ascertain the name of a 
plant, and thus learn its place among the natural orders. For ex- 
ample ; suppose that a person meets with the plant commonly call- 
ed stramonium, and wishes to know its character; by the Linnean 
System, he soon learns its botanical name. Datura; and this genus 
he fin-ds belongs to the natural order, SolanecB, characterized by 
qualities of an active and deleterious nature, as the Tobacco, Fox- 
glove, &c. 
The experienced botanist is not always obliged to refer to the 
artificial S5^stem for the natural character of an unknown plant. 
Being familiar with the characteristics of the different famines, he 
can often determine at once by the habit or general appearance of 
the plant that it belongs to the lily tribe (LiliacecB,) to. the mallows 
tribe (Malvaceoi,) to the wild turnip tribe (Aroidece,) or to any other 
of the conspicuous and well-defined natural orders or families. 
To Linnseus belongs the honour of having first suggested the ar- 
rangement of plants into natural orders. 
He pubhshed in 1738 what he modestly termed " Fragments of a 
natural method," consisting of 58 orders, founded upon the resem- 
blance of plants in their habits, general appearance, or medicinal 
quahties. 
The most popular Natural method is that of Jussieu, a botanist of 
Paris, improved by De Candolle of Geneva.* The characters em- 
ployed in this method, are, 
1. The structure of the Seed^ with respect to cotyledons. A plant 
* Professpr Lindley of England, has recently published a work on the natural sys- 
tern, which is deservedly popular. 
Resemblances which give rise to them — Physicians interested in the natural method 
— Connexion between the natural and artificial methods — Experienced botanists 
know plants by their habits— Natural method of Linnaeus— Method of Jussieu— 
What are the characters employed in Jussieu's method 7 — How is the structure of tho 
peed considered 7 
