NVMPHALINAE: VANESSA CARDUI. 481 



Other districts. That its power of flight is great we know from independ- 

 ent sources. Thus Trimen relates that a specimen flew on board a vessel 

 in which he was sailing, when about ninety miles from TencriflTc ; and 

 another writer speaks of one visiting a vessel six hundred miles from the 

 African coast during a cyclone ; other similar though not so striking in- 

 stances might be added. The immense swarms which covered Europe in 

 1879 are attributed to such immigrations, but these are spoken of more in 

 detail in anotlier part of this work, to which tiie reader is referred. 



Oviposition. I have observed egg-laying at various hours from 10 

 A.M. to 4 P.M. The ovipositing female alights upon a plant and moves 

 about with trembling wings, and body generally on a line with the midril), 

 until it finds a spot to its taste ; the wings, elevated at an angle of about 

 forty degrees with each other, now become quiet, the tip of the abdomen 

 is bent down upon the leaf, and the egg is instantly laid. I observed one 

 butterfly alight many consecutive times on unopened thistle heads, thrusting 

 her abdomen between the spines to the very sepals, as if in the act of ovipos- 

 iting ; but no egg was laid until she alighted on a leaf. The same butter- 

 fly appears never to lay more than a single egg upon one leaf, although 

 she frequently deposits eggs on different leaves of the same plant, and in 

 one particular instance laid them upon cut leaves lying on the ground ; in 

 this case she laid them upon the uppermost surface, whichever way the leaf 

 was turned ; on the plant they are always laid upon the upper surface ; 

 and I once found an egg on a spinous hair of a thistle-leaf. Several eggs 

 may sometimes be found on the same leaf, but they will always hatch at 

 different times, showing that they were laid on different occasions, if not 

 by different individuals. The eggs themselves vary considerably, their 

 vertical ribs ranging from fourteen to nineteen, and averaging fifteen and 

 a half or sixteen in number ; judging from the examination of forty or 

 fifty specimens, it would seem as if the average were slightly greater in 

 America than in Europe. The duration of the egg-state is from six to 

 eight days. 



Food-plant. The caterpillar feeds principally on Compositae and 

 especially upon the tribe of Cynaroideae, or thistles. 



"Just what they want the thistle brings, 

 But thistles are such surly things." 



In our country it has been found on Centaurea benedicta, Cnicus lance- 

 olatus (the common thistle), C. arvensis, Carduus nutans, Silybum mari- 

 anum, Onopordon acanthium, and Arctium lappa (burdock), — all plants 

 introduced from Europe; also on Senecio cineraria, belonging to another 

 tribe of Compositae ; on another of the Compositae, one of the sunflowers, 

 Helianthus sp. ; on still others, Anaphalis margaritacea, in company with 

 V. huntera; and (by J. Fletcher) on cultivated Artemisia; on one of the 

 Malvaceae, Altheae rosea (garden hollyhock) , and one of the borage family, 



