XXIV OUTLINES OF 



alluded to arc descriptions of species; the natural divisions of the Flora refer to 



natural grouj^s of\p€cies, * i t i u 



177. A Species comprises all the individual plants which resemble each otuer 

 sufficiently to make us conclude that they are all, or vicnj have been all, descended 

 from a common parent. These individuals may often differ from each other m 

 many striking particulars, such as the colour of the flower, size of the leaf, etc., 

 tut these particidars axe such as experience teaches us are liable to vary in the 

 seedlings raised from one individual. 



178. WTieu a hirge number of the individuals of a species differ from the others 

 In any striking particidar 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, 

 tul)ers, or any other method which produces a new plant by the development ^^^J^® 

 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 



Mill 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 LiniireuSj has 

 been universally adopted, viz., one common substantive name is given to a number 

 of sj^eciea 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 6000) for study 

 ■without further arrangement, they have been classed under the same principles, viis., 

 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 Latui 

 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., Ranunculaceee from 

 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 mimberof species, they require further classitication. 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, Sections. 



Subclasses or AUiancea. Divisions. Subsections. 



Natural Orders or Families. Suldlvmons. Species. 



Suborders. Oenera. Varieties. 



Tribes. Subgenera. 



183. The characters (3) by which a species is distinguished from all other species 

 of the same genus are collectively called the specific character oi the plant ; those by 

 which its genus is distinguished from other genera of the Order, or its Order from 



■J 



'A 



case '' 



may be. The habit of a plant, of a species, a genus, etc., consists of such general 



i: 



vegetation. 



iufl 



size, colour, ramification, Arrange- 



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