176 



COMPOUND ORGANS OP PLANTS. 



deduplication or chorization, (#coptw, I separate,) that is, by 

 the splitting of the organs during their development. This 

 process accounts satisfactorily for the appearance of certain 

 parts which do not follow the law of alternation. This chorisis 

 or separation is either collateral, the separated parts being 

 placed side by side, or transverse, the parts separated being left 

 one in front of the other. 



Of collateral chorisis we have a good example in the tetra- 

 dynamous stamens of the Cruciferse. The stock and wall- 

 flower belong to this natural order, and are plants with which 

 all are familiar. Fig. 76 is a diagram of a flower of the corn- 



Fig. 76. 



Fig. 77. 



mon stock, (Matthiola incana,) showing a calyx with four 

 sepals, a corolla with four petals, but the stamens are six : 

 four long and two short ; the former, placed together in pairs 

 as shown in the diagram, are supposed to have been originally 



