FAMILY HABITS IN BUTTERFLY LARVJE THE FRITILLARIES. 29 



noted above, that the latter hybernates within, and not outside, the 

 eggshell. 



Of the rapidity of movement among these larger Argynnid larvae, 

 and their general habit of hiding, Buckler says that a larva of 

 Argynnis adippe, above an inch long, when turned out for figuring, was 

 very shy at first, and curled up for several minutes, then, stretching 

 itself out gradually, it set off to run at a pace quite equal to the fastest 

 larva of Arctia caia. He also notes that, when feeding, it takes its 

 meals in a most rapid or hurried manner. He further observes that 

 /the larva of Argynnis aglaia also eats most rapidly, that, when 

 feeding, it keeps advancing with every mouthful until it gets to the 

 end of a leaf, then walks quickly back to the point of commencement, 

 and proceeds as before, always making a quick retrograde movement 

 before again eating its way forward, and that these operations were 

 performed with such rapidity, that half of a large leaf quickly dis- 

 appeared. When its hunger is appeased it retreats below the leaves, 

 or rests on the stalk of the plant. Of the American species, Edwards 

 says that the larva of Euptoieta claudia travels with wonderful 

 rapidity, so that a journey of several feet would be a small affair, 

 whilst he also remarks on the fact that the larva of this species hides 

 by day. " Scudder notes [Butts. New England, p. 550) that the larvae of 

 the larger North American Argynnids usually feed only by night, 

 hiding beneath leaves or in crevices in the ground by day. Of the late 

 summer-feeding larvae of Issoria lathonia, the winter-habits of whose 

 larvae are practically unknown, Frohawk notes (Ent., xxxvi., pp. 302, 

 303) : " They are very active in their movements, running rapidly 

 and feeding voraciously," also that " they appear to avoid the strong 

 sunlight, by sheltering on the underside of the leaves, and often 

 select the most shady part of the plant to rest upon ; but yet they 

 enjoy warmth, becoming very active and feeding rapidly on the 

 brightest and warmest days." 



It appears to us somewhat remarkable that the habits of the 

 Brenthid larvae should be so similar to one another, especially so 

 far as the hybernating habit is concerned. In this they differ 

 entirely from their allies, the Argynnids, which we have just con- 

 sidered, as they hybernate in the fourth instar, commencing their 

 winter rest often at the end of July, and, recommencing to feed 

 at quite the end of February and early March, and are fullfed by. the 

 end of May or thereabouts. The Brenthid larvae are essentially, 

 therefore, late summer and early spring feeders, and not spring- and 

 early summer-feeding larvae as are the Argynnids. Another great 

 point of difference is the inherent tendency in many of the Brenthid 

 species to produce a few larvae in each brood, with a " forward " habit 

 that results in a partial second- brood, the proportion of "forwards" 

 depending (1) on latitude, (2) altitude, and (3) on the individual 

 season. It is to be noticed, however, that, so far as the Palaearctic 

 Brenthid species, of which we have intimate knowledge of the larval 

 habits, are concerned — Brenthis selene, B. euphrosyne, B. dia, etc. — 

 the larvae resulting from these second- brood examples must reach the 

 normal fourth instar before winter (usually they do so at the end of 

 September or in early October), and hybernate in the same stage as 

 the more "laggard " larvae resulting from the early brood, or perish. 

 The restricted larval food-habit, too, is less marked in the 



