84 NATURE SKETCHES IN TEMPERATE AMERICA 



genutia. They were quite active in the warm sunhght, and 

 when I first saw them, two of them flitted about, here and there, 

 one moment ahghting on the flower of y\.rabis, and the next 

 moment depositing their eggs on the sterns. Again they would 

 indulge in a sunlight bath on the ground, where they would 

 alight and spread their wings as if enjoying the heat of the sun. 

 At one time I came across a group of Arabis plants covering 

 a small area on a wooded sand dune. On searching the 

 flowers, one of these butterflies was found, resting on the 

 flowers in the protected attitude above described. The wind 

 was strongly blowing at the time, and the insect clung on the 

 flower with more than ordinary persistence, turning its body 

 so that its head was directed toward the source of the air 

 currents. It was so persistent in its desire to remain on the 

 flower, that it submitted to be taken up with the plant, and 

 laid in a box. But after a time, on jarring the box accidentally, 

 the insect became startled, and flew away. 



As long ago as 1868, Wood ^ pointed out that the little orange- 

 tip butterfly, in England, often rests in the evening on the green 

 and white flower-heads of an umbelliferous plant, — the wild 

 chervil, Anthescus sylvestris, — and that when observed in this 

 position, the beautiful green and white mottling of the under 

 surface completely assimilates with the flower-head and renders 

 the insect very difficult to be seen. It is probable that the rich 

 dark coloring of the underside of our peacock, tortoise shell, 

 and red Admiral butterflies, answer a similar purpose. 



All of these butterflies seem to have a tendency to remain 

 very still when on the flowers, giving one the erroneous impres- 

 sion that they are conscious of the protection afforded by 

 their surroundings. Grossbeck ^ mentions^ that he found this 

 butterfly depositing its eggs singly on the stems of Arabis, 

 usually below the terminal bud. On very large plants as many 

 as four eggs are sometimes found. I have confirmed these 

 observations. Hornig^ found this species of butterfly laying 

 its eggs on the common plant known as mouse-ear, Sisymbrium 

 thalianum. I found upon looking into the subject that wherever 



^Wallace, in "Natural Selection and Tropical Nature," p. 43. 

 ^ Entomological News, May, 1908. 

 ' Ibid., Vol. XVI, p. 252. 



