﻿52 ON THE CLASSIFICATION OF BIRDS. 



birds consisted both of honey and of minute insects. 

 Since then some modern writers have flown to the other 

 extreme, and, wholly unsupported by facts, have declared 

 their belief that these birds live entirely upon insects. 

 In this they are as much mistaken as in their former 

 assertion ; the fact being, that they feed indiscriminately 

 upon both. The two filaments, which were supposed 

 to be tubular, are perfectly flat, and very thin, — a structure 

 obviously adapted for licking up the food. We have 

 reason, also, to believe that these processes are covered 

 with a mucilaginous substance, sufficiently adhesive to 

 act upon the pollen of flowers, and the wings of the 

 small dipterous insects, which the humming birds chiefly 

 select for their animal diet. The tongue of the African 

 sunbirds (Cinnyridce) we have never had the opportunity 

 of examining ; but by a fortunate chance we have dis- 

 covered that the type among the Australian honeysuckers 

 (Meliphagidce) , which represents the Trochilidce, has the 

 tongue constructed precisely the same as those birds. 

 This brings us to the second description of extensible, or 

 rather of suctorial tongues, and which is of a form almost 

 peculiar to the honeysuckers of Australia, and its islands. 

 In these birds the tongue is not nearly so extensible as in 

 the Trochilidce, being seldom more than half as long again 

 as the bill ; nor are the bones of the os hyoides carried 

 back upon the skull, as in the woodpeckers and humming 

 birds. Nevertheless, the structure appears especially 

 adapted for suction : the form of the lower part is the 

 same as in ordinary birds ; but the end is composed of a 

 great number of delicate fibres or filaments, exactly re- 

 sembling a painter's brush. Lewin, who drew and de- 

 scribed these birds in their native region, has figured the 

 tongue of the warty-faced honeysucker * (Meliphaga 

 phrygia), and describes the bird as sometimes to be 

 seen " in great numbers, constantly flying from tree to 

 tree (particularly the blue gum), feeding among the 

 blossoms, by extracting the honey with their long tongues 



* Lirds of New Holland, pi. 4. 



