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PART IV.-CLASSIFICATION. 



CHAPTER I. DEFINITIONS AND EXPLANATIONS. 



105. The fact that there are Necessity for 



numerous distinct kinds of plants has been recognised from Classifica- 

 very early days, and the uneducated native of our forests tlon ' 

 has required no botanical training to teach him, for instance, 

 that the Sal tree (Shorea robusta] is distinct from the Sam 

 (Terminalia tomentosa) or to enable him to recognise these 

 two kinds, or species, of tree in the forest. In early days, 

 when the total number of plants known to any single 

 individual was insignificant the want of an elaborate system 

 of classification was not felt, for one could readily acquire 

 and retain in the memory an intimate knowledge of the 

 characteristics of the known plants, which explains how it is 

 that the aboriginal is often found to be well acquainted with, 

 and able to recognise at sight, the majority of the plants 

 growing in the jungle near his village. It, however, soon 

 became evident that, if any individual desired to con- 

 siderably extend his knowledge of plants and to be able 

 to become quickly acquainted with those of foreign countries, 

 some system of classification was essential, under which all 

 plants could be shortly and concisely described (only essential 

 points of difference being noted) and grouped in such a way as 

 would enable one to quickly refer to its group any plant, where 

 its brief description and correct name would then be obtained. 

 Once the botanical name of a plant has been ascertained, all 

 the information that has ever been placed on record regarding 

 it can then be obtained by referring to the necessary books. 

 Botanical classification thus aims at placing all plants in groups 

 under groups, according to their resemblances, the smallest groups 

 being combined to form larger groups and the latter again 

 formed into still larger groups and so on, the plants included 

 in the smallest of these groups being all very much alike, 

 while those included in the largest groups have fewer points of 

 resemblance. The peculiarities which enable us to distinguish 

 one plant from another are called characters, 



In a Flora, therefore, which is a book containing the descrip- 

 tions of all the plants of any given country or district, the 

 essential characters which enable us to distinguish the plants 



