COLOUR VARIATION IN LIZARDS 127 



references to Professor Cope's work, from which this 

 chapter is chiefly compiled.^ 



^ The Crocodiles, Lizards, and Snakes of North America, by Edward 

 Drinker Cope, Professor of Zoology, University of Pennsylvania. (Sex 

 and colour, pp. 332-334, 336, 337, 342, 343, 400, §37. Age and colour, 

 pp. 354, 357, 363, 382, 431, 445, 478, 508, 564, 569, 575-577, 627, 

 635, 636, 641, 642, 645.) 



Other references : — 



" Colour Variation in British Adders, " Proc. Roy. Phys. Soc, Edin., 

 1903. British Serpents, chapter ix. Proceedings Dorset Nat. Hist, 

 and Antiquarian Field Club, vol. xxii. p. 43, 1901, Leighton. 

 Zoologist, March 1892, Boulenger. 



Since this chapter was written, Mr. Nelson Annandale has pub- 

 lished his Fasciculi Malayensis. The report on the Batrachians and 

 Reptiles collected by Mr. Annandale and Mr. Robinson has been 

 furnished by G. A. Boulenger, and it is of great interest to find here 

 also much evidence of the effect of age in the production of colour. 



