xl OUTLINES OF BOTANY. 
Cuap. II, Cuxasstrication, or Systematic Borany. 
176. It has already been observed (3) that descriptions of plants should, 
as nearly as possible, be arranged under natural divisions, so as to facilitate 
the comparison of each plant with those most nearly allied to it. The de- 
scriptions of plants here alluded to are descriptions of species; the natural 
divisions of the Flora refer to natural groups of species. 
177. A Species comprises all the individual plants which resemble each 
other sufficiently to make us conclude that they are all, or may have been 
all, descended from a common parent, These individuals may often differ 
from each other in many striking particulars, such as the colour of the 
flower, size of the leaf, etc., but these particulars are such as experience 
teaches us are liable to vary in the seedlings raised from one individual. 
178. When a large number of the individuals of a species differ from 
the others in any striking particular they constitute a Variety. If the 
variety generally comes true from seed, it is often called a Race. 
179. A Variety can only be propagated with certainty by grafts, cut- 
tings, bulbs, tubers, or any other method which produces a new plant by 
the development of one or more buds taken from the old one. A face 
may with care be propagated by seed, although seedlings will always be 
liable, under certain circumstances, to lose those particulars which dis- 
tineuish it from the rest of the species. A real Species will always come 
true from seed. 
180. The known species of plants (now near 100,000) are far too nu- 
merous for the human mind to study without classification, or even to 
give distinct single names to. To facilitate these objects, an admirable 
system, invented by Linneus, has been universally adopted, viz. one com- 
mon substantive name is given toa number of species which resemble each 
other more than they do any other species ; the species so collected under 
one name are collectively called a Genus, the common name being the - 
generic name. Each species is then distinguished from the others of the 
same genus by the addition of an adjective epithet or specific name. Every 
species has thus a botanical name of two words. In Latin, the language 
usually used for the purpose, the first word is a substantive and designates 
the genus; the second, an adjective, indicates the species. In English, the 
adjective or specific name comes before the substantive or generic one. 
181. The genera thus formed being still too numerous (above 6000) for 
study without further arrangement, they have been classed upon the same 
principles; viz. genera which resemble each other more than they do any 
other genera, have been collected together into groups of a higher degree 
called Families or Natural Orders, to each of which a common name 
has been given. This name is in Latin an adjective plural, usually taken 
from the name of some one ¢ypical genus, generally the best known, the 
first discovered, or the most marked (e.g. Ranunculacee from Ranunculus). 
It is rendered in English by the addition of the word plants to a plural ad- 
jective, or by adding the word family or order to the name of the typical 
genus taken adjectively, as Ranunculaceous Plants, or the Ranunculus 
Family (or Order). This is, however, for the purpose of study and com- 
parison. To speak of a species, to refer to it and identify it, all that is 
necessary is to give the generic and specific names. 
