Oh. XVIII.] CLASSIFICATION. 100 



CRUJIFORM FLOWERS. 



461. These are such flowers as have a calyx consisting ut 

 four leaves, and a corolla composed of four petals ; each petal is 

 fastened to the receptacle or bottom of trie calyx by a narrow 

 part called the claw. In the centre of the flower is a single 

 pistil long and cylindrical; the stigma is oblong, and duided 

 into two parts, which are reflexed or bent back on each side. 

 Each petal is placed between two leaves of the calyx ; this al- 

 teinate position is always seen in flowers where the number of 

 petals equals the number of leaves of the calyx. 



462. The cruciform flowers have six stamens, two of which, 

 standing opposite to each other, are shorter than the remaining 

 four t which always stand in pairs. This inequality in their 

 length determines them to be in the class Tetradynamia. 



463. The germ soon becomes a long pod, called a silique, 01 

 a short, thiclTone, called silicula ; this difference in the length 

 of the pods constitutes the distinction of the two orders of the 

 .jlass in which they are placed. 



464. The plants belonging to this class are herbaceous, tbt 

 leaves are alternate; the Cabbage, the Mustard, the Radish 

 and Stock-gilly-flower, belong to this family. They are 



un a chymical analysis, to contain some sulphur. 



461. What are cruciform flowers] 

 46-2. What is said of their stamens'? 

 4G3. What, is said of the germ 1 

 464. What of the leaves, Ac. t 



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