532 Appendix. 



individual feeds. The phenomenon was particularly 

 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. Another 

 striking instance was noticed in some very fine caterpillars 

 feeding on a large shrubby Solatium, which, excepting 

 the bright yellow bands bordering the dorsal violet bars, 

 were generally dull ochreous-yellow, like the leaves and 

 stalks of the Solanum. On plants with bright green or 

 deep green leaves, the colour of the larvae is almost in 

 exact agreement. Mr. Trimen adds : " These remarks 

 apply principally to the underside and pro-legs 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 food-plants, so 

 that their uniformly-coloured under-surface is upwards, 

 and turned towards the light, and their variegated upper 

 surface turned downwards." 



These observations are of the highest importance, not 

 only as adding another instance to the recorded cases 

 of phytophagic variation, but likewise as showing that 

 with this variability a protective habit has been acquired. 

 It is to be hoped that such a promising field for experi- 

 mental investigation as is offered by this and analogous 

 cases will not long remain unexplored. In attacking the 

 problem two chief questions have in the first place to be 

 settled : (i) Is the variability truly phytophagic, i. e. are 

 the colour-variations actually brought about by the 

 chemico-physiological action of the food-plant ? and 

 (2) Are the larvae at any period of growth susceptible to 

 the action of phytophagic influences ? The first question 

 could be decided by feeding larvae from the same batch 

 of eggs on different food-plants from the period of their 

 hatching. The second question could be settled by 

 changing the food-plants of a series of selected specimens 



