86 



NATURE SKETCHES IN TEMPERATE AMERICA 



same purpose, especially when this character is confined to 

 the males." 



Wallace,^ on the other hand, maintained that the orange 

 coloring may have served in directing the attack of birds away 

 from the vital parts of the body and, therefore, were also pro- 

 tective in character. 



I might add that the little butterfly, Anthocharis genutia, 

 while polyphagous, that is, having the ability to feed on various 

 plants, lives on cruciferous plants, such as Arabis, Sisymbrium, 

 and Cardamine. There is, however, a substance having a 

 mustard taste, common to all these plants, which the larvse of 

 these butterflies seem to enjoy. The butterfly probably func- 

 tions as a cross fertilizer, as well as using them as food plants. 

 This has contributed in establishing a reciprocal relation between 

 them and their exquisite little butterfly guests. 



The Animated Rolled Leaf 



N other chapters the subject of protective 

 resemblance has been treated and demon- 

 strated by the walking-stick, the geometrid 

 larva, the automeris mbth, and other exam- 

 ples. This subject would not be given full 

 justice without mentioning the rolled-leaf 

 moths, belonging to the genus Datana. 



After a slight shower one morning in July, 

 I made a search at the edge of a mixed 

 beech forest where the trees are somewhat 

 scattered. I had strolled but a short distance 

 among the undergrowth in quest of study 

 material before I found three examples of the night-flying 

 moths known as Datana contracta. It will be seen from 

 the first plate illustration, bearing two figures of these in- 

 sects, that they resemble a withered, rolled leaf. Recording 

 these insects just as they were found in nature, the first 

 example appeared on the green leaf of a brier, the second 

 one on the wild raspberry, and the third on the green leaf of 

 the sassafras. These situations indicate that the moths showed 

 '"Natural Selection and Tropical Natjire," p. 371. 



