202 Mr. A. R. Wallace on the Natural Arrangement of Birds. 



and, in the structure of the feet, the two are almost identical. 

 The Hornbills of Africa are said to feed principally on reptiles, 

 as do the King- Hunters [Dacelo) of Australia. We look upon 

 Hornbills, therefore, as one of the abnormal developments of 

 Fissirostral birds, of which they are the largest, the least elegant, 

 and the least gifted with facilities for locomotion and for obtain- 

 ing their food ; and that their nearest affinities lie in the direc- 

 tion of the Kingfishers. 



The remaining family, which, according to our views, belongs 

 to the Fissirostral tribe, is that of the Trochilidce, or Humming 

 Birds, hitherto always placed in the Tenuirostres, which we have 

 before adduced some reasons for believing to be an altogether 

 artificial group. In this innovation we are not aware of having 

 any support ; yet we think it possible to show good reasons for 

 it. What is it that characterizes the Fissirostral group but 

 minimized feet and maximized wings, always connected with 

 some modification of structure, adapted to give facilities for 

 seizing the food with the mouth ? and all these the Hummers 

 possess in a remarkable degree. In the ease and flexibility of 

 their motions on the wing they surpass even the Swallows. Their 

 little feet exactly resemble those of some of the Swifts (Dendro- 

 chelidon)j and the long, variously-curved bill and extensile tongue 

 give them the same facilities for obtaining their food as do 

 the short bill and wide gape in the other. They are, too (we 

 believe), like the Swallows, purely insectivorous ; for in every 

 specimen we have examined the stomach was full of insects, 

 principally minute flower-frequenting Coleoptera. No doubt 

 they do partake occasionally of the nectar, or the pollen of the 

 flowers they frequent, but as a delicacy rather than as solid food. 

 The firmness and solidity of their muscle, the thickness of their 

 skin, and the immense muscular exertion which they constantly 

 make, can doubtless be supported only by animal food, which the 

 very small space occupied by their stomach and intestines also 

 shows to be the c|ise. But a stronger proof of this assertion is, 

 that there are many species which never frequent flowers ! All 

 the species of the genus Phaethornis which we met with on the 

 Amazon were found only in the lower parts of the forest, among 

 the shrubs and palms which rise only a few feet from the ground. 

 Here we have often seen them searching the leaves for insects, 

 supporting themselves almost motionless in the air, their body 

 erect and their bill pointed upwards, and passing rapidly over 

 the under surface of each leaf in succession. They would often 

 dart suddenly out into an open space, and remain motionless a 

 few feet from my face, and then fly ofi" again to repeat their 

 search for their favourite food. At the various trees in flower 

 about which I have observed and shot Hummers, I have never seen 

 a species of Phaethornis, whereas I used daily to meet with them 



