INSECTS IN RELATION TO OTHER ANIMALS 233 



all. Chanliognatlms is not eaten by many birds (though flycatchers and 

 swallows select this insect) and the genus is regarded unfavorably by 

 caged catbirds and blue-jays. 



In regard to other insects, Judd finds that Epicauta. with its irritant 

 fluid, is immune from all but the kingbird; Cyllene seldom occurs in the 

 stomachs of birds; May flies and caddis flies, however, are terribly perse- 

 cuted, but swiftly flying Diptera and Oclonata are highly immune. 



From such facts as these, Judd properly infers, ''not cases of protec- 

 tion and non-protection, but cases of greater and lesser efficiency of 

 protective devices." 



