Appendix. 535 



Mr. C. V. Rilcy states' with reference to the larva 

 of Thyrens Abbott that the ground-colour appears to 

 depend upon the sex, Dr. Morris having described the 

 insect as "reddish-brown with numerous patches of 

 light green," and having expressly stated that " the 

 female is of a uniform reddish-brown with an interrupted 

 dark-brown dorsal line and transverse striae." Mr. 

 W. D. Gooch, who has reared the South African butter- 

 flies Nymphalis Citharon and N. Brutus from their larvae, 

 states T that these " differed sexually in both instances." 

 Of Brutus only a few were bred, but of Citluzron many. 

 "The sexual difference of the latter was that the females 

 had a large dorsal sub-cordate cream mark, which wai 

 wanting, or only shown by a dot, in the males, and the 

 colour was more vivid in the edgings to the frontal 

 horns." 



Although such cases appear to be at present inex- 

 plicable, they are of interest as examples of those 

 "residual phenomena " which, as is well known, have in 

 many branches of science so often served as important 

 starting-points for new discoveries and generalizations. 8 



* "Second Annual Report," 1870, p. 78. 

 T " Entomologist," vol. xiv. p. 7. 



* With reference to the habits of C. Capensis (p. 531), I 

 have since been informed by Mr. Trimen that this species 

 does not conceal itself by day, so that the dimorphism may be 

 regarded as a character retained from an earlier period and 

 adapted to the present life conditions. 



