VAEIOUS MARRIAGE CUSTOMS. Ill 



as fertilisers ; but in the tropics the work of 

 fertilisation is often performed by birds, such as 

 humming-birds, sun-birds, and brush-tongued 

 lories. Many of the most brilliant and beautiful 

 among the bell-shaped tropical flowers have been 

 specially developed to suit the tastes and habits 

 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 corre- 

 spondence may often be observed between in- 

 sects 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 beautiful blossom can 

 only be fertilised by humming-bird hawk-moths, 

 no other insect in Europe at least having a L 

 proboscis long enough to reach to the bottom of J 



