INTRODUCTION. XX111 



varieties. Now there are many plants which bear a 

 close resemblance to a Violet in the structure of their 

 flowers and seeds, but yet differ so far that they cannot 

 be reduced under the same genus ; they are therefore 

 placed with it in the same Tribe, called VIOLACE^B, all 

 the genera in which differ in essential points from the 

 genera which compose other Tribes, but agree with a 

 vast number in having two-lobed seeds and leaves with 

 netted veins, two of the characters of DICOTYLEDONOUS 

 PLANTS. In this Class it is arranged with plants fur- 

 nished with both calyx and corolla, and having their 

 petals distinct and inserted with the stamens into the 

 receptacle. 



The plant of which we have been speaking belongs, 

 then, to the 



CLASS I. DICOTYLEDONES. 



SUB-CLASS I. THALAMIFLOK^E. 

 Order or Tribe IX. VIOLACE^;. 

 Genus 1, Viola. 

 Species 2, odordta. 

 Variety, blue, white, or double. 



In the Linnsean system the same plant is placed in 

 the Class PENTANDRIA, which comprises flowers having 

 five stamens ; and in the Order MONOGYNIA, which in- 

 cludes such of them as have one pistil. 



In this work the British genera and species are 

 arranged in their Natural Orders or Tribes ; and a 

 synopsis is also given of ftie genera only, as they stand 

 in the Linnaean Classes and Orders. (P. xxviii. &c.) 



The student, it is presumed, wishes to determine the 

 genus and species, or to find the name, of the plants 

 which he meets with in his walks. Suppose him to 

 have found a small shrubby plant with oblong leaves 

 and large yellow flowers : in what part of this work 

 must he look for a description which he may compare 



