40 STRA Y FEA THERS FROM MANY BIRDS. 



parasite plants are more common, birds doubtless assist 

 largely in propagating them. In South America many 

 flowers are fertilised by Humming Birds, which would 

 certainly be sterile without their aid. In South Africa 

 others are known to be fertilised by Sun Birds ; and 

 doubtless many other instances remain to be discovered. 

 The long slender beaks of the Humming Birds and Sun 

 Birds enable them to probe into the beautiful tropical 

 blooms which they search for insects and nectar ; and 

 in so doing they carry the pollen from one flower to 

 another, as it clings to their heads or bills. 



Our sixth and last division will treat of the economic 

 value of birds from a sanitary point of view. In spite 

 of man's wonderful improvements in the sanitary con- 

 dition of the world, there is much left for humbler 

 creatures to do, and the birds of the earth and waters 

 perform a by no means inconsiderable share of the 

 unpleasant duty. Birds are some of the world's greatest 

 scavengers ; and in hot climates especially, they are 

 valued and cherished accordingly. The traveller in the 

 hottest parts of the world cannot remain in them long 

 without admiring the important part played by birds, in 

 clearing the streets and suburbs of towns of all kinds of 

 refuse and garbage which, if left in the burning sun, 

 would soon breed fever and pestilence. The King of 

 scavenger birds is the Vulture. In all hot countries 

 these birds of various species abound. They scent the 



