THK BOTANY OF THE FARM. 427 



given genus the character being taken from the parts of the flower and 

 fruit, as in the order. In the specific character are included certain less- 

 important modifications of form, whether in the stem, leaves, or flowers, 

 which serve to distinguish allied species. 



The names of the Classes are variously derived, according to the views 

 of the authors in regard to classification. They express some points of 

 structure or development which are of marked importance or permanence. 

 The orders are named from some characteristic genus included in them, 

 except in artificial methods, where some organ is taken as the means of 

 distinction. Genera are derived either from the Latin name of one of the 

 species, from the structure or qualities of the included species, or from the 

 name of some botanist, etc. Thus Prunus is a genus including the plum, 

 the sloe, etc. ; Rosa, the rose ; Papaver, the poppy ; Hookeria is a genus 

 named after Hooker ; Lithospermum, from two Greek words signifying a 

 stone and seed, is given to a genus, the species of which have hard stony 

 achenes. 



In giving the name of a plant, we mention its genus and species. Thus 

 the common Dog-rose is called Rosa canina, the first being the generic 

 name, the second the specific. Specific names may indicate the country in 

 which a plant is found, the locality in which it grows, the form of its 

 roots, stem, or leaves, the colour of its flowers, the name of its discoverer 

 or describer, etc. To the genus and species are added certain letters indi- 

 cating the botanist who founded them. Thus, Valeriana, L. is the genus 

 Valerian, as constituted by Linnaeus ; and Valeriana officinalls, L. is the 

 officinal Valerian as described by Linnaeus. 



In the systems of classification there are two pursued in the arrange- 



t of plant > ; one is called the Artificial method, and the other the Natural 



method. The higher divisions of classes and orders in these systems are 



f'Minded on entirely different principles, while the genera and species, or 



minor divisions, are the same in both. The genera and species are 



1 1 tly arranged in the two systems, In artificial methods one 



or two organs are selected in an arbitrary manner, and they are taken as 



vl orders ; while in tin- natural method 



re grouped according t> their alliance in all their important < 

 racters. Plants belonging to tin- san, uul order in tip sys- 



nni'in number of the .stamens and 



:m of their flowers, or some other arbitral -ily-s.-lected 'cha- 

 berj while in the latter, plants in the same class and order an 



allinity. and e,nvspond in all th> d points of their sti 



. When a si udent knows the aitifieial class and Older t \\ hieh a plant 



