ANTHOCHARIS I. 



plants, and did so, until the full set of drawings was made, sending day after day 

 one stage or other or the plants. I myself saw none of those larvte, but received 

 three pupne from Mrs. Peart which had formed about 22d May. From one of 

 them came a male butterfly 7th March, 1887. The periods of the earlier stages 

 of one example were thus : larva hatched 27th April ; 1st moult 30th April ; 2d, 

 ithMay; 3d, 9th; 4th, 12th; pupated 22d ; at Philadelphia. The plant was 

 Sisymbrium Thaliana, described in Wood as growing among rocks and in sandy 

 fields from Vermont to Georgia, and westward to Kentucky, with a stem 4'-12' 

 high. 



The present year, 1888, Mr. Schonborn supplied me with eggs and plants, and 

 I immediately found the same plant abundant close by my house. I believe, at 

 one time or other, I had confined females Genutia upon every cruciferous plant 

 in the neighborhood but the right one, and had never obtained an egg. This 

 butterfly is rare here, however. The eggs are laid on the flower-stalks, and Mr. 

 Schonborn writes that he has never found more than one egg on a plant, nor 

 more than one larva. He says : " I never found a larva in open fields, although 

 the plant grows there in abundance in large patches. I always found them on 

 isolated plants growing in places sparingly covered by large oaks, hickories, 

 cedars, and other trees." The young larva feeds on the flowers and buds, and 

 as these pass away, on the seed pods, usually beginning at the end of the long, 

 slender pod and eating towards the stem. (See Fig. g.) After the plant has gone 

 to seed, Mr. Schonborn says it utterly disappears, and the larvae never pupate on 

 the plants, but go to the trunks of the nearest trees and there change in the 

 cracks of the bark, or other protected places. The color of the pupa is such that 

 on an oak it would be almost undistinguishable. 



I kept my larvae on growing plants set in a flower-pot and covered by a muslin 

 bag kept upright by sticks, and one morning chanced on a larva in the act of 

 pupating, almost done, while another was just about to begin. Both were at- 

 tached by buttons of white silk and by girdles to the same stick. The second one 

 at this time was curved from end to end, the head almost touching the stick. 

 (See cut, 2.) Presently it straightened itself and a creeping movement passed 

 from tail to head in a way to loosen the skin from the body, the larva convul- 

 sively throwing itself against the girdle, then to the support (3). These throes 

 soon burst the skin at top, exposing the head over which the process was bent 

 down, flattened and small (4). When the cast reached the last segment it was 

 thrown to the ground by a rapid twisting movement of the pupa, and afterwards 

 the same continued for nearly a minute, accompanied by a vigorous pushing 

 downward. This double motion fixed the hooks securely in the button, which 

 was forced into a cup shape, so that it quite sheathed the end of the segment 



