112 THE STOEY OF THE PLANTS. 



the very deep spur which holds the honey. 

 Now, humming-bird hawk-moths do not light 

 on a flower, but hover lightly poised on their 

 quivering wings in front of it. So all the ar- 

 rangements of the flower are strictly set forth in 

 accordance with the insect's habit. The calyx 

 consists of five sepals with a very long spur, the 

 end of which, as you can find out by biting it, is 

 full of honey. Then come five petals, not, how- 

 ever, all alike, but divided into two distinct sets, 

 an upper pair and a lower triplet. The upper 

 pair are broad and deeply-lined with dark veins, 

 which all converge about the mouth of the spur, 

 and so show the inquiring insect exactly where 

 to go in search of honey. The lower three, on 

 the other hand, have no lines or marks, but 

 possess a curious sort of fence running right 

 across their face, intended to prevent other 

 flying insects from alighting and rifling the 

 flower without fertilising the ovary. This 

 flower, too, has two successive stages ; it opens 

 male, with stamens only, which bend upward 

 towards the insect ; later, it becomes female, 

 the stigma opens and becomes forked, and bends 

 down so as to occupy the very same place pre- 

 viously occupied by the ripe stamens. 



A great many well-known flowers have such 

 lines as honey-guides. If I have succeeded so 

 far in interesting you in the subject, you will 

 find it a pleasant task to hunt them out for 

 yourself in the violet, the scarlet geranium, the 

 spotted orchid, and the tiger lily. 



So far I have dealt only with the marriage 



