360 



HUTCHINSON'S POPULAR BOTANY 



FIG. 441. CYCLAMEN 



(Cyclamen europceum). 



in his amusing preface to Kerner's famous little 

 book, Flowers and their Unbidden Guests, " who 

 were not of sufficient importance, and the ban- 

 quet [whether of nectar or pollen] be wasted 

 on them ; for it is only when insects have a 

 certain shape, size, or weight that she requires 

 their visits, and can use them profitably for her 

 purposes. . . . All insignificant and unremunera- 

 tive visitors, all such, moreover, as would creep in 

 by the back entrance, must be kept out." 



Thus the opposite leaves of a plant may form 

 a kind of collar, or series of collars, to the inflor- 

 escence, insurmountable to wingless insects from 

 below, as is the case in many Gentians ; or even 



the stipules and alternate leaves may act in the same way, as in the 

 Common Pear and Thorow-wax respectively. 



How excellently, again, is a pendulous flower adapted for the exclusion 

 of small creeping insects ! Take the Snowdrop (Galanthus nivalis, fig. 440). 

 Where is the ant that could get inside the hanging flowers of this February 

 maid ? if the ant were in the habit of climbing up plants at that season. 

 The slippery curved walls would defy all its efforts ; and, as a matter 

 of fact, only winged insects pollinate the flower. Hive-bees, which are the 

 most useful to the plant, enter the drooping bells without difficulty. 



When the object of a hive-bee's search is the 



pollen, " it thrusts its head, fore-legs, and mid- 

 legs into the flower, clinging by means of its 

 hind-legs to the outer surface of an inner perianth- 

 segment. With the tarsal brushes of its fore- 

 and mid-legs it sweeps pollen from the anthers 

 and places it in the baskets on its hind-legs. If 

 it wishes to suck honey, it usually finds it more 

 convenient to use its own fore- and mid-legs for 

 clinging to the perianth." * In either case the 

 bee's head gets well covered with pollen, some of 

 which is sure to be deposited on the stigma of 

 the next flower which it visits, for the style of 

 the Snowdrop projects beyond the anthers, and 

 .the bee's head must come in contact with the 

 stigmatic surface on entering. 



The curvature of many perianth leaves also 

 subserves the purpose of excluding wingless 

 insects from the nectar and pollen. "I placed," 



FIG. 442. PLUMBAGO sa ^ s Kerner, " some small and by no means timid 



(Plumbago capensis). * Miiller : Fertilization of Flowers. 



