104 THE STORY OF THE PLANTS. 



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 curi- 

 ous 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 

 previously 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 ar- 

 rangements of those plants which are fertilised by 

 insects or birds, and \vhich belong to the great 

 group of flowering plants descended from an early 

 common ancestor with five petals. We must next 

 deal briefly with the marriage customs of the in- 

 sect-fertilised class among the other great group 

 whose ancestor started with but three petals ; and 

 after that we must go on to the other mode of 

 fertilisation by means of the wind or of self-im- 

 pregnation. 



This chapter has consisted so much of special 

 cases that I do not think it stands in the same 

 need of a summary as all its predecessors. 



