PART ir.] CLASSIFICATION OF PLANTS. 109 



Thus we made use of the Buttercup and others as 

 examples of the Dichlamydeous Subclass, the Stinging- 

 Nettle of the Monochlamydeous Subclass, and the Willow 

 of the Achlamydeous Subclass of Dicotyledons. And, 

 further, we employed Buttercup, Pea, Bramble, Apple, 

 and Parsnip as examples of the Polypetalous Division, 

 and Marigold, Deadnettle, and Primrose of the Gamo- 

 petalous Division of the Dichlamydeous Subclass, and so 

 on for each of the principal divisions of Dicotyledons and 

 Monocotyledons. 



These illustrative examples we may regard as repre- 

 sentative types. Each type embodies the characteristics 

 of a large group, the members of which group, though 

 they differ from each other in minor details, such as 

 regularity or irregularity of the corolla, and sometimes 

 in the number of stamens and of carpels, generally agree 

 in characters which, from experience, we infer to be im- 

 portant, from their prevalence and general constancy 

 through a large number of plants. These important 

 characters are principally based upon varying conditions 

 in respect of adhesion, cohesion, and suppression of the 

 parts of the flower. 



By extending this method, by selecting and carefully 

 studying types representing the principal subordinate 

 groups, called NATURAL ORDERS, of British Flowering 

 Plants, we shall lay the sure basis of a thoroughly scien- 

 tific acquaintance with them. The types which we pre- 

 sently proceed to select from each important Natural 

 Order are not always the best suited to serve as repre- 

 sentatives of such Order, because we shall be obliged to 

 make use of plants of which specimens may be easily 

 obtained, and these do not always happen to be best 

 adapted for the purpose. Besides, in some Natural 

 Orders the amount of variation in minor characters is 

 so considerable that we shall find it needful to employ 

 Sub-types, the relation of which to their type we shall 

 endeavour to make clear whenever we find it needful to 

 employ them. 



You must not be content with the examination of those 

 plants only which are employed as types. You must try 

 to refer to its type every flowering plant yoit meet ivith, 

 and, in a short time, you cannot fail to recognise easily 



