spiders, etc., found in the stomachs do not represent by any means all their food. 

 The quantities of food found in these tiny stomachs are so minute and the insects 

 comprising them are so small that identification is very difficult and uncertain, but 

 it is believed that the following statements do not contain any serious errors. 



The animal food formed 94.32 per cent of the whole, and what was taken for 

 vegetable matter made up the remainder, 5.68 per cent. 



The principal item of insect food was small Hymenoptera ,of which a large 

 proportion are probably parasitic species. They amount to 36.32 per cent of the 

 food, and next to spiders are the largest constituents of the animal diet. Hemip- 

 tera stand next to Hymenoptera among the insects eaten and amount to 8.88 per 

 cent of the food. Many of these appear to be minute leaf hoppers (Jassidse) 

 or members of some closely allied family. Diptera (gnats) were found in only 

 a few stomachs. They amount to only 2.57 per cent of the food. The largest 

 component of the ruby-throat's food, however, is spiders, which amount to 43.46 

 per cent of the stomach contents. 



Four stomachs held what was thought to be fruit pulp, one contained plant 

 hairs felted into a solid mass, one held what appeared to be pieces of seed, and 

 one contained a few bits of rubbish. Altogether, vegetable food amounts to 5.68 

 per cent of the whole, and it is doubtful if any of it is taken intentionally. 



As a representative of the western members of this family, the Anna hummer 

 {Calypte anna) has been selected. Of this species 111 stomachs were examined, 

 and in some respects the food was found to differ noticeably from that of the 

 ruby-throat. The largest item of animal food is Diptera (gnats or small flies), 

 which amount to 45.23 per cent and replaces the spiders so characteristic of the 

 ruby-throat's diet. Hymenoptera, on the other hand, are nearly the same (35.03 

 per cent) as in the other species. Hemiptera (bugs) amount to 17.30 per cent, 

 or nearly double what the ruby-throat had eaten. The iVnna hummer had eaten 

 spiders to the extent of only 2 per cent. A few bits of beetles were found in both 

 species ; also a few fragments of what was supposed to be the skin of caterpillar. 

 Only a trace of vegetable matter, presumed to be fruit pulp, was found in the 

 stomachs of the Anna. 



631 



