DARWIN AND COLOUR ADJUSTMENT 109 



any chameleon, and evidently accommodating the changes 

 to the colour of the ground which it passed over. Yellowish 

 green, dark brown, and red, were the prevailing colours ; 

 this fact appears to be new, as far as I can find out.' ^ 



Darwin was well aware of the power of indi- 

 vidual colour adjustment now known to be 

 possessed by large numbers of Lepidopterous 

 pupae and larvae. An excellent example was 

 brought to his notice by C. V. Riley, ^ while the 

 most striking of the early results obtained with 

 the pupae of butterflies — those of Mrs. M.E. Barber 

 upon Papilio nireus — was communicated by him 

 to the Entomological Society of London. ^ 



Before leaving the subject of Protective Eesem- 

 blance I wish to take the opportunity of referring 

 to an observation on the chameleon, read by 

 J. S. Beuttler, Nov. 1, 1873, before the Eugby 

 School Natural History Society and published 

 in the Eeports for that date. In this paper 

 the author remarks, ' The side of the animal 

 nearest the light is invariably the darkest.' The 

 same fact was observed in South Africa (1905) 

 by Dr. G. B. Longstaff, who kindly supplied 

 the above quotation. Professor C. V. Boys and 

 the present writer. An interpretation of the 

 later observation was sought along the lines of 

 A. H. Thayer's classical explanation of the white 

 under surfaces of animals, and the conclusion 



^ Life and Letters, i. 235, 236. See also the Journal of Researches, 

 1876, 6-8, -where a far more detailed account is given, together 

 ■with a reference to Encycl. of Anat. and Physiol. 



' More Letters, ii. 385, 886. 



' Trans. Ent. Soe. Land., 1874, 519. See also More Letters, ii. 403. 



