NATUKAX. AIETUODS. ll^l 



tives ; generic naines are noims. The specific niinie sometimes indicates tlie num- 

 ber of leaves, as oucms hifolia (two-leaved orcliis) ; or the color of the corolla, as 

 ViOLA tri-colur (three-colored violet) ; or the form of the root, as solanum tuberosum 

 [\j\i\\ a tuberous root). Specific names are often derived from the names of per- 

 sons : thus, a species of Origanum is named tournefortii, after its discoverer, Tour- 

 :iefort. Geiuivic names are commenced with a capital letter : specific names are 

 not thus distinguished, but are usually in italics, being Latin words. 



151. After having analyzed a number of j^lants, the student 

 will naturally begin to observe a striking resemblance in many 

 genera, and arrange them in groups without any reference to 

 tlie artificial class or order where they may have been placed. 

 A\^e tluis form Natural families. K the whole vegetable king- 

 dom could thus be distributed into natural tribes, we should 

 need no artificial system. But we find genera whose relation 

 to other genera seems doubtful or obscure, and there are many 

 ])lants which seem to have few natural alliances with other 

 plants. 



152. The ■resemblances ichich give rise to natural families., 

 are — resemblance in seeds / in jfyericarjps., or the enveloj^es of 

 seeds; \i\ stamens amd pistils ; in corollas and calyces; in the 

 modes of inflorescence., or the manner in which the flowers grow 

 together upon the stalks ; in leaves / in roots ; and in stems. The 

 physician is chiefly conversant with the natural diaracters of 

 plants, especially with such as are connected by medicinal qual- 

 ities ; he considers one gxQ^x^ 2^% narcotics ; another as tonics; 

 another as stimulants^ &c. The natural method is aided by the 

 artificial system ; this enables the student to ascertain the name 

 of a plant, and thus learn its place among the natural orders. 

 For example, suppose a person meets with the plant conmionly 

 called stramonium, and wishes to know its' character ; by the 

 Linntean System he soon learns its botanical w^itlq., Datura ; 

 and this genus he finds belongs to the natural order, Solanaceoi., 

 characterized by qualities of an active and deleterious nature, as 

 the Tobacco, Foxglove, itc. The experienced botanist can often 

 determine at. sight, by the habit or general appearance of the 

 plant, to what tribe it belongs. 



153. Linnaeus published in 1738 w^hat he modestly termed 

 "Fragments of a natural method," consisting of 58 orders, 

 founded upon the resemblance of plants in their habits, general 

 appearance, or medicinal qualities. A popular l^atural method 

 was, after this, proposed by Jussieu, a botanist of Paris, and this 

 has been improved by De Candolle of Geneva, and by Lindley, 

 Professor of Botany in the University of London. The charac- 

 ters employed in this method are. The structure of the Seed, 

 with respect to cotyledons; insertion of the Stamens ; absence a/tid 



l.il. Natural families.— 152. Resemblances which give rise to natural families— Connection between 

 tlip natural nn.l nrlilici.il methods— Experienced botanists know plants by their habits.— 153. Natural 

 nii-ilio.l oi l,iiiiKin« -iMrthixJ of .lussiivi Characters employed in Jussieu's method. 



