Ch. VI, 2] STRUCTURE OF FLOWERS 269 



jects. Between these shapes and real insects there exist 

 certain relations presently to be noted. 



It is also characteristic of flowers to be fleeting, for com- 

 monly they last but a few days, after which they wither and 

 fall. Sometimes indeed they keep fresh but a few hours, and 

 it is only very rarely that their substance is sufficiently firm 

 to persist after drying, though this does occur in the kinds 

 we call " Everlasting.' ' Not the entire flower, however, 

 perishes with the showy structures, for the central parts 

 persist and grow gradually to the fruit which contains the 

 seeds. Indeed, it is the most normal and characteristic 

 feature of the flower that it precedes the fruit. The popular 

 idea that the flower is in some way essential to the production 

 of seed is thus correct. 



In case of the flower, as of other plant parts, the popular 

 and the scientific conceptions are by no means coincident. 

 The botanist includes under the term any structures, no mat- 

 ter how minute and obscure, which have part in the pro- 

 duction of seed, and excludes from the term any structures, 

 no matter how flower-like, which have no such function. 

 Thus, the so-called "moss flowers" are not botanically 

 flowers at all, and much less are "wooden flowers," "flowers 

 of tan," and some other objects to which the name is fanci- 

 fully applied. 



2. The Structure of Flowers 

 Despite their striking external multiformity, flowers are 

 comparatively simple and uniform in their mode of con- 

 struction. 



A typical simple flower, such for example as the Peony 

 (Fig. 183), has six or seven distinct kinds of parts. 



Outside is the calyx, composed of a whorl of five green and 

 leaf-like sepals. In the unopened bud they form a close y^ 

 protecting cover to the parts inside them, wherein consists 

 obviously their function. Usually they are somewhat 

 triangular in shape, opening out in a star form, but often 



