XXIV 
OUTLINES OF 
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, cuttings, 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 Race may with care be propagated by 
seed, although seedlings will always be liable, under certain circumstances, to lose 
those particulars which distinguish 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 numerous 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 Linnaeus, has 
been universally adopted, viz., one common substantive name is given to a 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. 
181. The genera thus formed being still too numerous (above 6,000) for study 
without further arrangement, they have been classed under 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 N atural 
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 typical genus, generally 
the best known, the first discovered, or the most marked (e.g., Ranunculacece f^om 
Ranunculus). This is however for the purpose of study and comparison. To speak 
of a species, to refer to it and identify it, all that is necessary is to give the generic 
and specific names. 
182. Natural Orders themselves (of which we reckon near 200) are often in the 
same manner collected into Classes : and where Orders contain a large number of 
genera, or genera a large number of species, they require further classification. The 
genera of an Order are then collected into minor groups called Tribes , the species of 
a genus into Sections , and in a few cases this intermediate classification is carried 
still further. The names of these several groups the most generally adopted are as 
follows, beginning with the most comprehensive or highest : — 
Classes. Subtribes . 
Subclasses or Alliances. Divisions. 
Natural Orders or Families. Subdivisions. 
Suborders. Genera. 
Tribes. Subgenera. 
Sections. 
Subsections. 
Species. 
Varieties. 
183. The characters (3) by which a species is distinguished from all other species 
of the same genus are collectively called the specific character of the plant ; those by 
which its genus is distinguished from other genera of the Order, or its Order from 
other Orders, are respectively called the generic or ordinal character, as the case 
may be. The habit of a plant, of a species, a genus, etc., consists of such general 
characters as strike the eye at first sight, such as size, colour, ramification, arrange- 
ment of the leaves, inflorescence, etc., and are chiefly derived from the organs of 
vegetation. 
