CARLTON. — COLOR CHANGES OF THE FLORIDA CHAMELEON. 2u7 



similar circumstances, a brown lizard was introduced into the dark-box, 

 it turned green. Moreover, when a brown animal was put inside the 

 dark-box and the whole opening was left free for the entrance of light, 

 the animal turned green and remained so, even in this diffuse light. 

 There seems, therefore, no escape from the conclusion that the illumi- 

 nation of one part of the animal not only turns that part brown, but 

 induces similar changes in the non-illuminated parts. I know of no 

 way of explaining the induced changes except on the assumption that 

 nerves serve as intermediate organs. 



Why two of the animals in the original experiments remained green 

 when their trunks were exposed to light, I do not know. It is pos- 

 sible that they were individuals whose reactions went on very slowly, 

 and that I did not give them sufficient time; for when I tried these 

 experiments I had not learned how slowly these changes sometimes 

 come on. Or, since these two cases occurred among animals whose 

 heads were in the dark, it is possible that they indicate that the con- 

 dition of the head more easily impresses itself on that of the rest of 

 the body than the reverse. I am, however, at present not in a posi- 

 tion to decide this question. 



The results of the experiments with the dark-box lead to two con- 

 clusions ; first, that the nerve terminals in the skin of Anolis are sensi- 

 tive to light and, secondly, that the change from brown to green may 

 be brought about indirectly through nerves. That the nerve terminals 

 in the skin of a vertebrate like Anolis should be sensitive to light is 

 novel, so far as I know, and somewhat remarkable; but since a green 

 animal with its head in the dark but its trunk in the light may change 

 to brown all over, the evidence of this seems to me conclusive. It is, 

 however, not without precedent, for in a recent paper Parker (:03) has 

 shown, partly through the observations of others and partly through 

 his own, that this property is possessed by several amphibians. From 

 the evidence I have presented, I believe that the nerves of the skin in 

 Anolis are sensitive to licrht. 



If the change from green to brown is under the control of nerves, one 

 should expect that the cutting of these nerves ought to prevent this 

 change. Unfortunately the nerves are so small in Anolis that even 

 those of the legs cannot be operated on with success, and hence a direct 

 test of this proposition could not well be made. It is, however, possible 

 to cut and destroy parts of the spinal cord. After such an operation 

 one might expect to find the part of the body supplied by nerves from 

 the destroyed portion of the cord incapable of changing to brown. To 



