Studies in Reptilian Colour Changes

1. Anolis becomes dark brown on a light-absorbing background and bright green on a light-dispersing background, the changes being accomplished by a dispersion or concentration of pigment within melanophores. 2. Blinded lizards lose the ability to respond to changes in backgrounds, but become brown when in light and green when kept in darkness. 3. Hypophysectomy results in permanent pallor. The brown colour can be temporarily elicited in such lizards by injection of appropriate extracts of the pituitary gland. 4. Denervated regions of skin undergo normal colour changes. 5. Electrical stimulation of hypophysectomized lizards evokes a mottled pattern. 6. Mottling is under hormonal and not under nervous regulation.