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THE AMERICAN NATURALIST [Vol. LI V 



persistence at the present time in quite considerable 

 abundance. Why they should be so sparingly selected as 

 food plants does not seem to have been adequately ex- 

 plained. 



The use of Phanerogams as food-plants is so general 

 that it is possible to gain a much clearer insight into the 

 conditions pertaining to them than is the ease with other 

 plants. In general the food habits of butterfly larvae are 

 more fully known than those of the moths, on account 

 of the smaller number of species and the general interest 

 taken by amateurs in this group. 



An account, very complete at the time, has been given 

 by Scudder of the food-plants of the butterflies of eastern 

 North America. 4 A tabulation of the food-plants in- 

 cluded in this list shows several interesting features. 

 Fifty-five families of plants are included (not taking into 

 account several larvae feeding on conifers and our one 

 predatory species) and the list contains a very repre- 

 sentative series, drawn from both the Monocotyledons 

 and Dicotyledons in approximate proportion to the num- 

 ber of species of these two sections. It is noticeable, 

 however, that several common families, the Iridaceas 

 Orchidacoa-, ( 'aryophyllacoa*, Fmphorbiaeeae, Vitaceae, 

 Primulaceae and Kubiaeeae are entirely omitted, that only 

 one species occurs in the Labiatae, or on the Umbellifer®, 

 and that only a very few affect Composite. We may 

 readily see that the generally strong-scented Labiatae and 

 Inibelliferae and the milky Euphorbiacea> might require 

 great adaptation on the part of larvae eating them."' 1ml 

 the omission of the other families if not entirely a matter 

 of chance must rest upon some less evident basis than 

 the foregoing. Among the other plant families the num- 

 ber of species of caterpillars compared to the number of 

 eastern American genera, included in each family that is 



