Vol. X] VON GELDERN—SKIN OF ANOLIS CAROLTNENSIS 97 



the vertical section and also the irregular appearance in the tan- 

 gential section, stating that it had the appearance of a more or less 

 homogeneous mass, irregular in outline, and penetrated in many 

 places by the processes of the melenophores but he was unable to 

 make out any cellular structure and denied the existence of nuclei 

 except between the blocks. Why he should believe this layer to be 

 the ochrophore layer of Keller, I am unable to say. He admits 

 that its arrangement differs from Keller's ochrophore layer. 



If Carlton's ochrophore layer is responsible for the green state 

 in Anolis, why is this layer present on the ventral aspect of the 

 animal where no green color is ever present? 



Keller states that this ochrophore layer is almost entirely 

 absent on the ventral aspect of the body of the chameleon, yet 

 Carlton, in spite of these differences in structure and position, 

 attempts to make these two layers analogous. Furthermore, 

 Carlton's ochrophore layer closely fits the description of Keller's 

 leucophore layer, which latter Carlton states does not exist in 

 Anolis. 



Undoubtedly the layer in Anolis is the same as that in the 

 chameleon except for possibly minor differences. 



Briicke described in the chameleon a white or yellow pigment 

 which he finds separated into two layers, the inner being thicker 

 and made up of closely packed colorless particles with rounded 

 boundaries, which reflect light, resulting in the white appearance. 

 He believes these reflecting granules^© be the product of cells 

 whose processes force themselves between the dermal structures 

 and lie between the epidermis and the underlying connective 

 tissue. In these two layers he evidently includes both the ochro- 

 phore layer and the leucophore layer of Keller. 



Pouchet has also described this layer and considers the white, 

 dust-like material as the products of cells which, by the growth of 

 the neighboring tissue, have been pressed into plates, and Keller 

 describes these plates or blocks which he names leucophores. He 

 considers their content similar to that found in the scales of cer- 

 tain fish described by Klihne and which are said to be composed 

 of guanine. The fact that both react positively to the murexide 

 test leads to this assumption. He believes, as does Pouchet, that 

 these leucophores have been pressed into plates by the pressure 

 of the overlying and underlying tissues and that their edges adapt 

 themselves to the neighboring structures due to the mechanical 

 resistance of the latter, and, in consequence, assume very irregular 



