AGRIUS CONVOLVULI. 341 



described under the groupings just indicated, and Poulton notes 

 that, by ii p.m. on October ioth, the most forward larvae entered 

 the resting-period, and, at this time, were 40mm., 40* 2 5 mm. and 

 42*5mm. in length respectively, the two shorter ones in the 

 morning having become 41.25mm. and 45mm. in length, whilst 

 others varied between 36'5mm. and 43'3mm. The entry on the 

 resting-period varied from October ioth-i5th, and the ecdysis from 

 October i3th-i8th, the last two (excepting the laggard) moulting on the 

 latter date. Of the 14 larvae that fed on in the last stadium, seven 

 were preserved. Of the others one had become adult and ceased 

 feeding on October 27th, and was then 73mm. long when extended 

 in walking, although already it had become somewhat contracted ; 

 another ceased feeding on the same date, a third on October 28th ; 

 on October 30th, another was walking about as if preparing for 

 burying and was 75mm. long when comfortably extended, the 

 remainder ceased feeding on October 31st, the longest being 85mm. 

 long when extended. The lengths of the mature larvae were cer- 

 tainly less than wild ones. Buckler describes a larva as 4 inches 

 long, Whitaker one of 3J inches, none of Poulton's were much over 3 

 inches. Of the habits of the larvae in the last stage, Poulton notes that 

 it has been stated that the larvae conceal themselves in the earth or 

 among brown leaves during the day, and writes : " I think that this 

 is most improbable, for I did not see the least tendency towards such 

 habits, although I surrounded the larvae with appropriate materials 

 during the last stage." This idea originated with Harris, in 1775, 

 and was perpetuated by D'Orville, who (Zoologist, p. 6818) records 

 that, on October 14th, 1859, he obtained a nearly fullgrown larva of A. 

 convolvuli, that was found in a potato field and was so covered with 

 wet dirt, that he inferred that it concealed itself under ground by day 

 and fed by night. The notion that the larva hid by day beneath the 

 soil (E.M.M., v., p. 161) was proved by Syme and Buckler to be with- 

 out foundation, the former observing that the larvae fed away continuously 

 without attempting to bury themselves (loc. at., vii., p. 139), the 

 latter (Larvae, &c, ii., p. 23) finding that the larva is quite unwilling 

 to stay on the earth and that, when so placed, it crawled up through 

 the Convolvulus which had been placed over it and took up its 

 position as usual on the stem of the plant. It showed no disposition 

 to wander away from its foodplant (Convolvulus arvensis), nor any 

 aversion to daylight, and, although placed openly on a table for 

 several hours a day, the larva merely moved further up the stem 

 by slow degrees to get at the leaves in their order upon the stem. 

 Buckler gives three or four inches as representing adequately the extent 

 of a day's progress. As another proof of the lethargic habits of the 

 larva, the same observer mentions that he invariably found it on the 

 same part of the foodplant as when placed in its cage the previous 

 evening, and he concluded also that it was not a nocturnal feeder. 

 Throughout the day the larva feeds frequently, taking rest in the 

 intervals, and Buckler says it does not consume much at the time. 

 Sturt, who received 17 larvae from Cornwall, in October, 1895, 

 says (Ent. Rec, vii., p. 226) that they were sluggish, but good 

 feeders, seldom moving unless in search of food. When disturbed, 

 they twisted the head sharply to one side, and it was particularly 

 noticed, when changing their food, that they would quickly let 

 go their foothold ; in fact, they showed a decided tendency to drop 



