112 



THE FLOWER 



the same kind, and that this is most commonly accom- 

 plished by the aid of insects. The various forms of the 

 perianth are, as a rule, very definitely related to the work 

 of attracting the attention of insects, or of receiving and 

 supporting them when they alight, or of guiding them to 

 the "honey" or nectar secreted by special glands at the 

 base of the flower. In view of such offices the labiate 

 corolla of the Mints, the tubular or funnelform corolla of 

 the Morning Glory, the spurred (nectariferous) petals of 

 the Columbine, and the irregular flower of the Violet, are 

 readily understood. This subject will be treated more fully 

 under The Ecology of the Flower. 



215. The receptacle of the flower is that part which be- 

 longs to the stem. It is commonly short, and some- 

 what enlarged or knoblike. Flowers 

 with very numerous pistils generally 

 have the receptacle enlarged so as to 

 give them room ; it sometimes becomes 

 broad and flat, as in the Flowering 

 Raspberry ; sometimes 

 elongated, as in the 

 Blackberry (Fig. 256), 



the Magnolia, etc. It is the receptacle in 

 the Strawberry (Fig. 156), much enlarged 

 and pulpy when ripe, which forms the eata- 

 ble part of the fruit, and bears the small 

 seedlike pistils on its surface. In the Rose 

 (Fig. 157), instead of being convex or 

 conical, the receptacle is deeply concave, 

 or urn-shaped. Indeed, a Rose hip may be likened to 

 a strawberry turned inside out. 



216. In Nelumbo, of the Water Lily family, the singu- 

 lar and greatly enlarged receptacle is shaped like a top, 

 and bears the small pistils immersed in separate cavities of 

 its flat upper surface (Fig. 158). 



217. Arrangement of the parts of the flower. This is 

 most easity studied in those flowers, in which all parts 

 are present calyx, corolla, stamens, and pistils ; 





156. Section through 

 a Strawberry. 



157. Longitudinal 

 section of a 

 Rose. 



Ill 



