STRUCTURE OF FLOWERS. 91 



the development of the filaments. Admitting this 

 manner of viewing it, we shall understand how the 

 perigone is sometimes adehi'ent to the ovary, or com- 

 posed of parts opposite the stamens — characters peculiar 

 to the calyx ; whilst in other plants, it is free, odorous, 

 has its lobes alternate with the stamens, and becomes 

 double and multiplied by the abundance of the sap — 

 characters peculiar to the corolla. 



The perigone is sometimes reduced, by abortion, to a 

 simple rudiment : this is observed among Dicotyledons, 

 in the Euphorbiaceas, and especially in those with the 

 flowers in compact heads. It is this which happens 

 among Monocotyledons in the Graminese, where the 

 perigone appears represented by the lodicules ; their 

 number is ternary in Bambusa and Glyceria ; sometimes 

 the third is smaller, and its absence in several cases may 

 result either from an abortion more or less complete, or 

 from their intimate union. 



Section IX. 



Of the relative Position of the parts of one floral 

 Verticil compared with that of another. 



The position of the parts which compose the floral 

 verticils is susceptible of every modification which 

 results from each of them, being either between or 

 opposite the pieces of the outer verticil. The first case, 

 that is to say, that where each piece is between the two 

 outer ones, is so much more frequent than all the others, 

 that we may believe that it is the natural state, inasmuch 

 as it is conformable to the disposition of the successive 



