Classification of Plants 195 



Pkilippia, or the number of seeds may differ. Yet these 

 genera have enough conspicuous characters in common to 

 place them all under the one order Ericaceae. 



As a matter of fact there are no hard and fast lines to be 

 drawn in nature. These groupings into orders, genera, and 

 species have been made so that we may think and speak of 

 them more easily. 



Individuals of a species in which the difference is slight but constant 

 are spoken of as varieties. When two species are crossed, their offspring 

 (hybrids) are as a rule sterile, they will not form seeds. The common 

 offspring of two varieties are usually fertile. 



Of late years the collecting and naming of plants in schools 

 has gone out of fashion. This is unfortunate. To know the 

 name is not enough, but it helps us to know the plant. One 

 who has ma'de a collection has found how and where the plants 

 grow, when they blossom and fruit, and it is to be hoped has 

 gained some general ideas as to how their forms and markings, 

 colours, and odours are related to their benefactors of the 

 animal world. Not only the flower, but the whole aspect of 

 the plant, tells how it has survived the wind and weather, how 

 it has battled with tinfavourable conditions of soil and drought 

 and its sturdier neighbours in the struggle through the ages 

 toward self-expression and perfection. It is hardly worth while 

 knowing that the stamens of some flowers are declinate while 

 others ascend and arch downward, unless we see how they are 

 adapted to visiting insects in relation to pollination. 



The first attempt at classifying plants came about through 

 their real or supposed medicinal values. For this purpose 

 they were classified as trees, shrubs, and herbs. From the 

 time of Aristotle until the sixteenth century students began to 

 arrange plants into groups which were very artificial. The 

 most famous of these groups was that of the Swedish botanist, 

 Linnasus. This system was used until the middle of the 

 seventeenth century. In constructing these keys, plants were 

 grouped according to a few evident characters as the number 

 of parts of the flower, which enabled students to refer plants 

 readily to their proper orders. Since then efforts have been 

 made to SQ classify plants that those plants shall be brought 

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