Appendix. 525 



becoming smaller, more flattened, and less distinct, till 

 lost on the twclth segment, sometimes becoming 

 indistinct after the seventh or eighth segment ; these 

 spots arc only distinct as eye-spots on the fifth and 

 sixth segments, that on the sixth being flatter than that 

 on the fifth, those on the remaining segments appearing 

 like dashes while the larvae is green, but more like eyes 

 on its changing colour when full fed." The change here 

 alluded to is the dark-brown coloration so generally 

 assumed by green Sphinx-larvae previous to pupation, 

 and which, as I have stated elsewhere (Proc. Zoo. Soc., 

 1873, p. 155), is probably an adaptation advantageous 

 to such larvae when crawling over the ground in search 

 of a suitable place of concealment. Making the necessary 

 correction for the different mode of counting the 

 segments, it will be seen that the primary ocelli of this 

 species arc in the same position as those of the other 

 species of this genus as described in a previous part of 

 this essay, and that it belongs to the second phyletic 

 group treated of at p. 193. The interesting fact that 

 this species does not display dimorphism, whilst the 

 closely allied form from Kashmir is dimorphic, shows 

 that in the present species the process of double adapta- 

 tion has not taken place ;and this will probably be found 

 to be connected with the habits of life, *". e. the insect 

 being well adapted to the colour of its food-plant may 

 'not conceal itself on the ground by day. The caterpillar 

 of Deilephila Robertsi, Butl., is found at Candahar on a 

 species of EupJiorbia growing on the rocky hills, and is 

 so abundant that at the end of May every plant with any 

 leaves left on it had several larvae feeding upon it. "The 

 larvae are very beautiful and conspicuous, and are very 

 different in colouring according to their different stages 

 of growth." The general colour is black with white 

 dots and spots ; a subdorsal row of large roundish spots, 

 one on each segment, either white, yellow, orange or 



