530 Appendix. 



Capensis], on which it also feeds. There are two 

 eye-spots in this species in the usual positions ; they are 

 described as being blue-grey in a white ring, and raised so 

 as to project a little. The subdorsal is white, and is bor- 

 dered beneath by a wide shade of bluish-green irrorated 

 with white dots, and crossed by an indistinct, white 

 oblique ray on each segment. These last markings are 

 probably remnants of an oblique striping formerly 

 possessed by the progenitor of this and other species of 

 the genus (see, for instance, Fig. 25, PI. IV., one of the 

 young stages of C. Porcellus}. It is possible that these 

 rudimentary oblique stripes are now of service in assist- 

 ing the adaptation of the larva to its food-plant, but this 

 cannot be decided without seeing the insect in situ. 



The subdorsal line extends from immediately behind 

 the second eye-spot to the base of the very short and 

 much curved violet anal horn. With reference to the 

 protective colouring Mr. Trimen writes : " The difficulty 

 of seeing these large and beautifully-coloured larvae on the 

 vines is quite surprising ; six or more may be well within 

 sight, and yet quite unnoticed. The subdorsal stripe 

 greatly aids in their concealment, as it well represents in 

 its artificial light and shade the leaf-stalks of the vine." 

 When this larva withdraws its front segments the eye- 

 spots stand out very menacingly ; but in spite of this it is 

 greedily eaten by fowls and shrikes (Fiscus Collaris), 

 and Mr. Trimen also found that a tame suricate 

 (Rhysana Suricata} and a large monitor lizard (Regenia 

 Albogularis) did not refuse them. The failure of the 

 eye-spots in causing terror in these particular cases cannot 

 be regarded as disproving their utility in all instances. It 

 must always be borne in mind that no protective 

 character can possibly be of service against all foes ; 

 natural selection only requires that such characters should 

 be advantageous with respect to the majority of the 

 enemies of any species, and further experiments with 



