32 BRITISH BUTTERFLIES. 



towards maturity, and leaving the larva more completely green. 

 Floersheim observes that the quite young larva of /. ajax rests usually 

 either on the underside of the leaves of Asimina triloba (papaw) or 

 upon the dark grey stems of that plant with which its colour exactly 

 harmonises ; at rest, it does not adopt the " Sphinx-like attitude " so 

 frequently presented by the young larva of Papilio machaon, but is 

 outstretched ; when undergoing ecdysis it rests either on the under- 

 side of a leaf or upon the stem of its foodplant. When it gets 

 older the larva rarely rests on the stem, but chooses the underside of a 

 leaf, and is indifferent throughout life whether the head points towards 

 the stem or tip of a leaf. Floersheim adds that, if a larva is found 

 resting on a stem, it is always of the grey variety which resembles the 

 wood in colour ; further, that the larvae of this species, unlike those of P. 

 machaon and I. ajax, conceal themselves carefully all their life, that, 

 when young, it is not content with closely resembling a small grey 

 slug, but hides itself usually either on the underside of the leaves or 

 upon the stems of its foodplant, and that, when full-grown, its yellow- 

 banded green-grey shape, swelling considerably towards the head 

 (which resembles a blunt leaf-tip), and tapering to a stem-like tail, 

 seen at right-angles to the leaf upon which it feeds or rests, presents 

 the exact appearance of a bent or unfolding young leaf of Asimina 

 triloba, with the sunlight playing on its semi-transparency. Taylor 

 notes (Trans. Ent. Soc. LontL, 1904, p. 409) that the colour of the 

 full-fed larva of the Jamaican species, Papilio homcrus, harmonises 

 closely with the tint of the leaf of its foodplant. Davidson and 

 Aitken state (Joiun. Bomb. Nat. Hist. Soc, x., pp. 581 et seq.) that the 

 larva of Papilio buddha, which feeds on the tirphal tree, rests motion- 

 less on the upperside of a leaf, which is of exactly the same shade of 

 green as itself, that it is slightly speckled with a paler shade in imita- 

 tion of the effect produced on the leaf by minute insects eating away 

 the soft tissue, whilst it often holds the head and front part of the 

 body raised in the well-known Sphinx attitude. 



The Papilionid larvae are usually sluggish in habit. When young 

 their safety appears to depend largely on their immobility, and, when 

 older, their large size and weight tend to make it dangerous for them 

 to move really quickly. The larvae of Papilio machaon are sluggish, 

 particularly when young, and Floersheim records that he has known a 

 larva starve on a withered leaf rather than migrate to a living one 

 touching it. The young larva shakes its head sharply from side to 

 side, as also when older, if an aphis or other insect touches it. The 

 larva of P. alexanor appears to have very similar habits, and in nature 

 will eat a plant almost bare before migrating to another. Edwards 

 says that the larv<e of Jasoniades ylaucus and J. rutulus are also 

 exceedingly sluggish in habit, usually only moving when impelled by 

 hunger, whilst, if disturbed, the larva of the former rocks its body 

 slowly from side to side and throws out its osmaterium. The larvae 

 of Euphoeades troilus are also sluggish, but Scudder says (Putts. X<i<- 

 Engl., p. 1328) that such movements as the fullgrown larva makes, 

 when exposed to view, appear absurdly affected ; it moves, or seems 

 to glide, by little Btarfcs, about a second apart, in a very slow or measured 

 way, ami he adds that this movement is evidently no necessity of its 

 organisation, but a, superinduced habit for some protective purpose, 

 probably in co-relation with its great thoracic spots and hunch, and he 



