THE FLOWER 



247 



of the partridge berry, and the recurved edges of corollas 

 like those of the morning-glory and tobacco, over which small 

 crawhng insects cannot easily climb. 



Of flowers that are pollinated by night moths, some close 

 during the day, as the four-o'clock and the evening primrose ; 

 and vice versa, the morning-glory, dandelion, and dayflower 

 (Commelyna) unfold their beauties only in the sunlight. 

 For similar reasons, night-blooming flowers are generally 

 white or very light-colored, and shed their fragrance only after 

 sunset. A nodding position is assumed by many flowers at 

 night, or during a 

 shower, to keep the 

 pollen from being in- 

 jured by dew or rain- 

 281. Insect depre- 

 dators. — The secre- 

 tion of honey is a 

 common means of 

 attracting insects, 

 and various adapta- 

 tions, such as spurs, sacs, and pockets, are provided for pro- 

 tecting it against unwelcome intruders. In general, plants 



that have long, tubular 

 'J \ flowers, like the trumpet 



honeysuckle {Lonicera sem- 

 FiG. 365.-Headoftheswordbiii,abird pervirens) and the trumpet 



vine, are reserving their 



sweets for humming birds, 

 or long-tongued moths and butterflies. This protective 

 device is not always successful, however, against insect dep- 

 redators, for it is not uncommon to find such corollas with 

 a puncture near the base, made by wasps or bees, and some- 

 times by humming birds themselves, in their impatience to 

 get at the feast before the flower is open. Through the breach 

 thus made, a rabble of petty thieves can then find entrance. 



Fig. 364. — A flower of the trumpet vine (Tecoma 

 radicajis) adapted to pollination by humnung birds 

 and humming bird moths, which has been pierced by 

 a bee or bird for honey. 



Head of the swordbill, a l)ird 

 adapted to feeding on nectar from long, 

 tubular corollas. 



