262 PROCEEDINGS OP THE AMERICAN ACADEMY. 



scope, it is in all probability an inorganic crystalline deposit. I have 

 not been able to make out its relation to cells. The pigment occurs in 

 blocks, and it is easy to see that nuclei are scattered irregularly between 

 these. The nuclei are similar to those figured by Keller ('95, Taf. 4, 

 Fig. 10) for the ochrophores of the African chameleon, and they may 

 belong to the cells which produce what I have called the ochrophore 

 pigment; but whether this pigment is in the cells or in intercellular 

 spaces I have not been able to determine. 



The ochrophore pigment showed no differences in the brown and the 

 green states of the skin, so far as I could observe. The pigment masses 

 did not change in position, the blocks were neither nearer together nor 

 farther apart, and the physical properties remained the same. 



The relation of the melanophores to the ochrophore layer is best seen 

 in a section of brown skin parallel to the surface. In such a section 

 (Fig. 2) the ochrophore layer (odiph.) has the appearance of a more or 

 less homogeneous mass, irregular in outline and penetrated in many 

 places by the processes of the melanophores. These processes spread 

 out irregularly over the distal suiface of the ochrophore layer. 



The melanophores (Fig. 1, melaph.') occur under the scutes, but not 

 in the spaces between them, and are rather uniformly distributed to the 

 number of about one hundred to a scute. The melanophores are for 

 the most part round or oval in outline. They have a sharply marked 

 contour, and the black pigment that they contain is in the form of small 

 granules. Chlorine, when applied to sections by Mayer's method, 

 destroys the color in these granules. Depigmented sections stained with 

 Delafield's haematoxylin show that each melanophore contains a nucleus, 

 thus demonstrating its cellular nature. 



In the dark-brown skin (Fig. 1) each melanophore gives rise on its 

 distal surface to some six or seven processes which extend distally to 

 the region immediately under the e[)idermis. Near the body of the 

 melanophore the processes show very few branches; but as they approach 

 the epidermis tliey divide into smaller and smaller branches, which mingle 

 together and form a dense interlacement; in a section perpendicular 

 to the surface of the skin (Fig. 1) these branches seem to form an 

 almost continuous black band. I have seen no evidence that the finer 

 branches anastomose, for in sections of the skin parallel to its surface 

 (Fig. 2) tlie processes and branches appear as a great number of dots of 

 varying sizes without any connecting network. The processes and their 

 branches are everywhere crowded with black pigment granules like those 

 in the body of the melano2:)hores. 



