50 BUTTERFLIES 



ferae, etc.), of tlie other on Gramineae and Cari- 

 ces, and of course very decidedly affect the general 

 result when all butterflies are considered. It is 

 entirely owing to them that these two families 

 take the first place, though they are by no means 

 insignificant in their relation to the other families 

 of butterflies. For leaving the Hesperidae out 

 of consideration, the Rosaceae easily assume the 

 first place and hold it alone, while the Legumi- 

 nosae and Gramineae still retain such importance 

 as to hold the second place, and indeed the high- 

 est position there with the Salicaceae, Compositae, 

 and Violaceae, followed hard by the Cupuliferae, 

 Ericaceae, Grossulaceae, and Cruciferae. These, 

 then, are the preferred food of the caterpillars of 

 our eastern American butterflies. 



Two facts brought out from this study of the 

 food plants of our caterpillars are more striking 

 when brought into contrast: the narrow choice 

 of very many species which feed upon a single 

 species or genus of plants and the very large 

 number of families of plants which are brought 

 under contribution to feed the entire body of our 

 caterpillars. The fact that considerably more 

 than half of the families of plants are sought by 

 only a single family of butterflies, and indeed 



