REPTILES. 405 



in 0. bifurcus, we can hardly doubt that they serve the 

 same general purpose in the economy of these two animals. 

 The first conjecture, which will occur to every one, is that 

 they are used by the males for fighting together; and as 

 these animals are very quarrelsome,* this is probably a cor- 

 rect view. Mr. T. W. Wood also informs me that ne once 

 watched two individuals of C. pumilus fighting violently 

 on the branch of a tree; they flung their heads about and 

 tried to bite each other; they then rested for a time and 

 afterward continued their battle. 



Fig. 8fl. Chamroleo Owenli. Upper figure, male; lower figure, female. 



t With many lizards the sexes differ slightly in color, the 

 tints and stripes of the males being brighter and more dis- 

 tinctly defined than in the females. This, for instance, is 

 the case with the above Cophotis and with the Acantho- 

 dactylus capensis of S. Africa. In a Cordylus of the latter 

 country, the male is either much redder or greener than 

 the female. In the Indian Calotes nigrildbris there is a 

 still greater difference; the lips also of the male are black, 

 while those of the female are green. In our common little 

 viviparous lizard (Zoo f oca vivipara) " the under side of the 

 body and base of the tail in the male are bright orange, 



*Dr. Bucholz, "Monatsbericht K. Preuss. Akad.," Jan., 1874, p 

 78. 



