266 PROCEEDINGS OF THE AMERICAN ACADEMY. 



animal and thus hold it in place as well as keep light from entering the 

 box. The lizard could be placed either with the head projecting out of 

 the box and in daylight, while the trunk remained in the box in dark- 

 ness, or the reverse. 



To test the possible effects of this apparatus independent of light con- 

 ditions, I placed a brown Anolis in the box with its head projecting 

 outward ; then, leaving the lid off, I put the dark-box and the lizard 

 in another and larger dark-box, which I thereupon closed. The lizard 

 underwent the usual change, finally becoming green. On exposing the 

 open box and lizard to daylight, the animal changed to brown. Thus 

 the retention of the animal in the small dark-box by the cloth collar had 

 no observable influence on the color changes. 



After this test of my apparatus I proceeded to determine whether 

 the light which fell on one part of the animal's body could be said to 

 have any influence on the color changes in other non-illuminated por- 

 tions. Six green animals v/eve placed in the box in turn, each with 

 its head outside and its trunk inside. All turned brown, on the trunk 

 as well as on the head, though in every case a trace of green, for 

 some unknown reason, remained on the neck, and in one instance one 

 leg remained somewhat green. Notwithstanding these slight irregu- 

 larities, this experiment showed beyond a doubt that the illumination 

 of the head not only induces a change to brown in that region, but 

 also in the part of the animal in the dark. 



Next, six green lizards were placed in the box in turn, this time 

 with the head inside and the trunk outside. Three animals changed 

 wholly to brown excepting for some small spots on the neck, one 

 changed partly to brown, and two remained green. Here, again, in 

 three instances at least, the illumination of one part led to the appro- 

 priate color change in the non-illuminated part. 



It might be concluded at once from these observations that the illumi- 

 nated parts do influence the non-illuminated ones, and that therefore 

 the change to brown is under the control of nerves. But it must be 

 remembered that even with the best management of the apparatus some 

 light always entered the dark-box through the open space between the 

 animal's neck and the cloth collar, and that this light might be respon- 

 sible for the change in the so-called non-illuminated part. To test 

 this I put a green animal wholly in the dark-box, while another green 

 one was placed in the opening with its head inside the box. Notwith- 

 standing the fact that both head and trunk of the animal in the opening 

 changed to brown, the introduced lizard remained green. When, under 



