Mr. A. R. Wallace on the Natural Arrangement of Birds. 203 



in the gloomy jungle, where not a flower exists ; and yet, from 

 never being able to see them at a greater distance than three or 

 four yards, they were the most difficult of all to obtain, without 

 blowing them to pieces. Many species also hunt for insects in 

 the air, exactly like true Fissirostral birds. I have often observed 

 them in the evening, on the banks of streams, coming out of the 

 jungle just as the Goatsuckers were beginning to appear, and 

 darting about after the mosquitos and other minute insects, 

 returning after each short circuit to the edge of the forest, where 

 they remained balanced in the air for a moment and then darted 

 ofi" again. At other times they will sit on the topmost twig of 

 a dead tree, and making short circuits in the air, return to it, 

 exactly in the same manner as do the Jacamars and Puff Birds. 



Thei'c is also another interesting fact to be mentioned. 1 had 

 brought me a nest containing two little Hummers, apparently 

 very recently hatched. I tried to feed them, and gave them, 

 first, according to established rule, syrup made of .honey and 

 water, and also of molasses ; but the poor little creatures did 

 not at all like it, though they opened their mouths as if raven- 

 ously hungry. They were nearly choked by the liquid, and tried 

 all they could to spit it out, which they generally succeeded 

 in doing. Finding all my efforts to suit their taste in vain, I 

 resolved to try if they liked insects better, and caught some 

 minute flies which were very abundant. On dropping one of 

 these into their mouths, they immediately closed their beak and 

 by a great muscular eff"ort of the throat swallowed it, and opened 

 their mouths again for another. In this way they would each 

 take fifteen or twenty little flies one after the other before they 

 were satisfied. I thus kept them alive three or four days, and 

 could I have bestowed sufficient time and constant attention 

 upon them, there is no doubt they would have lived much 

 longer. At all events the experiment satisfied me that the young 

 Hummers arc fed by their parents with insects, and not with 

 honey. 



I also observed that the beak of these little birds was very 

 short, triangular, and very broad at the base, — in fact exactly the 

 beak of a Swallow slightly lengthened. We see therefore in the 

 Humming Birds an extreme and peculiar development of the 

 Hirundine form of the Fissirostres. The wings of the Swallow, 

 already among the longest in the whole class of Birds, are still 

 further lengthened. The feet, already so short, are still further 

 reduced. The plumage, which in the Swallow has become more 

 compact and appressed than in any other of the Fissirostres, has 

 these qualities still further developed. The skin, which in the 

 tribe generally is thin and tender, is in the Swallows compara- 

 tively thick and strong, and in the Hummers is perhaps stronger 

 in proportion to their size than in any other birds. The bill is 



