STRUCTURE OF FLOWERS. 105 



the Leguminosae ? the irregularity is evident, for the 

 placenta is lateral. Is it attached to the base of the 

 carpel, as in the Compositae ? the pistillary cord follows 

 one of the sides of the pericarp, and causes an irregu- 

 larity. Is it attached to the apex of the carpel, as in the 

 Dipsacese ? the vessel that supplies it with nourishment 

 passes along one of the sides of the carpel, and makes it 

 necessarily irregular. Thus, every monospermous car- 

 pel, every solitary carpel, is naturally a deviation from 

 the symmetrical order, and, consequently, an irregu- 

 larity most probably caused by abortion. 



Section XII. 



Of the Primitive Disposition of the Parts of a Floral 

 Verticil; or of the Aestivation. 



The complete and regular flower is, as we have seen, 

 composed of at least four concentric verticils, each formed 

 of several pieces, the relative disposition of which we are 

 about to consider. The rapid development of these dif- 

 ferent organs at the period of flowering is such, that we 

 cannot judge of this primitive disposition unless we study 

 it in the buds. Linnseus, who compared it with the 

 vernation of leaves, has given it the name of Estiva- 

 tion. Richard has proposed to substitute that of 

 Prefloration ; which perhaps would be preferable, if 

 it were worth while to change a term which is not erro- 

 neous. 



This disposition of the parts is especially important to 

 be observed in that which relates to the envelopes of the 



