F'ROCEEDINGS 



OF THE 



CALIFORNIA ACADEMY OF SCIENCES 

 Fourth Series 



Vol. X, No. 10, pp. 77-117, pis. 7-9 February 12, 1921 



X 



COLOR CHANGES AND STRUCTURE OF THE SKIN 

 OF ANOLIS CAROLINENSIS 



BY CHARLES E. VON GELDERN 



The mechanism of the color changes in the lacertilia has been 

 the subject of much investigation, especially in that of the African 

 Chameleon. One need only refer to the works of Briicke, Keller, 

 and Fuchs for historical resumes. Briicke, Pouchet, and Keller have 

 attempted to solve this problem by a close study of the histological 

 structure of the skin and Keller was able to demonstrate clearly 

 the various elements essential for the production of the various 

 color states. 



The histological structure of the skin of Anolis has, as far as I 

 have been able to determine, been studied only by Carlton, who 

 attempted to correlate the findings of Keller in the chameleon 

 with those in Anolis. 



The Anolis carolinensis , or so-called Florida Chameleon, belongs 

 to the family Iguanidae and is in no way related to the true chame- 

 leons. Its habitat is the southeastern part of the United States 

 and Cuba. It may be distinguished from all other North American 

 lizards except the Geckos, according to Ditmars, by the expanded 

 and flattened adhesive pads on the middle four phalanges of each 

 foot. 



It is entirely insectivorous, subsisting mainly on flies and meal 

 worms, which it is able to capture with almost unerring accuracy. 

 Water in the form of scattered droplets is lapped by means of its 

 thick tongue and these lizards soon become dehydrated and die if 

 water be not supplied in this form. 



A characteristic flattened, semicircular projection of the skin, 

 known as the throat-fan (Ditmars), dewlap or gular appendage 



