BOTANY. 163 



i ^ 



THE CALYX. 



The parts of the calyx called the sepals form a primary ex- 

 ternal envelope. The analogy of these pieces with the leaves 

 is evident ; like these latter, they are often plane, green, and 

 furnished with stomata; they present, too, the same internal 

 organization, and fulfil the same physiological function. They 

 are often united, more or less completely. When the calyx 

 has the sepals thus united, it is called gamomosepalous or 

 monosepalous, and when they are free, polysepalous. The co- 

 herent portion of a monosepalous calyx is called the tube, and 

 its border the limb. 



COROLLA. 



Formed by one or several verticels of pieces called petals, 

 generally of a brilliant colour, and exhaling odours more or 

 less grateful. The corolla is called monopetalous, or gamope- 

 talous, or polypetalous, according to the union or freedom of 

 the petals. The expansion of the petal is termed the limb ; 

 and may be either entire or divided, regular or irregular ; 

 when the point of attachment in the petal is narrow, it is 

 termed an unguis (claw). 



THE STAMENS. 



One or more organs within the petals, and having with them 

 great analogy of position and transformation ; they are inserted 

 upon the torus, close to the petals, often adhering to them, 

 and are even transformed into these organs, as in double 

 Roses, where we often observe such a change to take place. 

 When there is but one verticel of stamens, they are equal in 

 number with the petals and (except in a few cases) alternate 

 with them. When there are several verticels, each is com- 

 posed of the same number of pieces, and the total number of 

 the stamens is a multiple of that of the petals. The stamens 

 perform an important part in the business of reproduction. 

 When these organs are attached beneath the germen [PL 45, 

 Fig. L]. they are denominated hypogenous\ when upon the 

 calyx [Fig. K],perigenous; and when upon the superior part 

 of the germen [Fig. G], epigenous. A flower without stamens 

 is called a female flower. 



