VARIOUS MARRIAGE CUSTOMS. 103 



of these comparatively large and powerful ferti- 

 lisers. The tongues of all, but especially of the 

 humming-birds, are admirably adapted for suck- 

 ing honey from flowers, as they are long and 

 tubular, sometimes forked at the tip, and often 

 hairy so as to lick up both honey and insects. 

 The length of the beak and tongue varies to- a 

 great extent in accordance with the depth of the 

 tube in the flowers they fertilise. Bird and flower, 

 in other words, have each been developed to suit 

 one another. The same sort of correspondence 

 may often be observed between insects and flowers 

 developed side by side for mutual convenience. 



One more point I should like to touch upon 

 before I pass away from this part of the subject; 

 and that is the lines or spots so often found on 

 the petals of highly developed flowers. These for 

 the most part act as honey-guides, to lead the bee 

 or other fertilising insect direct to the nectar. A 

 very good case of this may be seen in an Indian 

 plant which is found in every English cottage 

 garden-^-that is to say the so-called nasturtium. 

 This blossom can only be fertilised by humble-bees 

 and humming-bird hawk-moths, no other insect in 

 England at least having a proboscis long enough 

 to reach the bottom of 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 arrangements 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, 



