MANDUCA ATROPOS. 423 



in the case of this species also, the form referred to is replacing the 

 yellow (green) variety, for, whilst in the middle of Europe (Germany, 

 France, Hungary) the dark form is extremely rare, in the south of 

 Spain this variety {teste Noll) is almost as common as the yellow 

 one, and in South Africa, at Port Natal {teste Staudinger) the dark 

 form is somewhat the commoner, although the golden-yellow, and, 

 more rarely, the green, varieties occur there. I have seen a caterpillar 

 and several moths from Port Natal, and these all agree exactly with ours. 

 The displacement of the green (yellow) form by the dark soil-adapted 

 variety appears, therefore, to proceed more rapidly in a warmer than in a 

 temperate climate." Noll writes further that the larva of M. atropos does 

 not, in the south of Spain, conceal itself by day in the earth (see footnote, 

 anted p. 422), as with us, but on the stems or underneath the leaves. He 

 says : " At Cadiz, on the hot sandy shore, Solatium violaceum grows to a 

 height -of three feet, and, on a single plant, I often found more than a 

 dozen M. atropos larvae resting with the head retracted. It can easily 

 be understood why the lateral stripes are blue when one has seen 

 the south European Solaneae, on which this larva is at home. 

 Solanum violaceum is scarcely green, for violet tints alternate with 

 brown, green, and yellow over the whole plant, and between these 

 appear the yellow-anthered flowers and golden-yellow berries of 

 the size of a greengage. Thus it happens that the numerous thorns, 

 an inch long, between which the caterpillar rests on the stem, pass 

 from violet into shades of blue, red, green and yellow." Meldola 

 states (loc. at., app. p. 531) that Trimen noticed for many years 

 that, at the Cape, the larva of this species varies greatly in the 

 depth and shade of the green ground-colour, the variability being 

 in strict accordance with the colour of the leaves of the particular 

 plant on which the individual was feeding ; the phenomenon was parti- 

 cularly noticeable in larvae feeding on Buxia grandiflora, a shrub 

 in common cultivation in gardens, and of which the foliage is of 

 a very dull pale greyish-green, whilst another striking instance was 

 noticed in some very fine caterpillars feeding on a large shrubby 

 Solanum; when found on plants with bright green or deep green leaves, 

 the colour of the larvae is almost in exact agreement. Trimen adds : 

 " These remarks apply principally to the underside and prolegs 

 and lower lateral regions, the dorsal colours of violet and yellow 

 varying but little. The protection afforded is very considerable, as 

 the larvae almost always cling to the lower side of the twigs of their 

 foodplants, so that their uniformly-coloured undersurface is upwards 

 and turned towards the light and their variegated upper surface 

 turned downwards." That the number of larvae of the dark form varies 

 much, in Britain, from time to time is noted by Anderson (Ent. Rec, 

 vii., p. 40) who observes that, although he has in various years 

 had a great number of larvae of this species, he had only had the 

 green form until 1896, when he had several which, instead of 

 being of a beautiful apple-green tint with violet and yellow streaks, were 

 of a dingy brown colour with a latticed pattern of dull blackish-purple 

 on the sides and back, and a sprinkling of dirty white spots, the 

 anterior segments being white, with two stripes broken up into spots a 

 little darker than the general colour of the body ; whilst he adds that 

 both the green form and the variety have a similar whitish warty caudal 

 appendage. Burrows gives (Ent. Rcc* v., p. 220) a detailed descrip- 



