62 LETTER IV. 



but you will remark a difference in their fruit, of this 

 nature ; in some of them, as the Shepherd's Purse 

 itself, the pod is so very short, that there is not 

 much difference between its length and breadth ; in 

 others, it is very long and slender, as in the Turnip 

 and Cabbage ; to the former of these fruits the name 

 of Silicle is given ; to the latter, that of Silique ; and 

 by many Botanists the whole tribe of Cruciferous 

 plants is divided into two portions, of which one is 

 called Siliculosey and the other Siliquose. By the more 

 scientific Botanist of the present day, this distinction 

 is held in less estimation, and new divisions, founded 

 upon the structure of the embryo, are employed ; 

 but these are so obscure, that I will not fatigue you 

 with them. 



The most beautiful species in the w^hole tribe are 

 the Wall-flower, which sheds its sweetest odours over 

 the ruined buildings of England, and the Stock, 

 that, with its hoary leaves and gay flowers, gives an 

 air of green old age to the rocks and cliffs of the 

 Mediterranean. Both these, however lovely in their 

 wild and single state, are chiefly cultivated when 

 their flowers have become what is called double ; 

 that is to say, when the parts which are usually sta- 

 mens, and pistils, and sepals, are all transformed 

 into petals ; by which means the quantity of gaily 

 coloured parts is much augmented. There are those 

 who, with an air of scientific delicacy, pretend to 

 despise these beautiful objects, and call them mon- 

 sters ; but I would not have you follow such an 

 example; for, in reality, double flowers, indepen- 



