94 CALIFORNIA ACADEMY OF SCIENCES [Proc. 4th Ser. 



For this reason formalin fixed skin was sectioned between 

 blocks of celloidin very soon after fixing and then mounted in 

 glycerine. In these sections, there is situated just beneath the 

 epidermis a thin layer made up of bright yellow droplets of varying 

 sizes (Fig. lo). These droplets appear beautifully refractive, do 

 not contain any granular material, nor are they arranged like the 

 elements in the ochrophore layer of Keller. Some of these drop- 

 lets may even be found at times between the basal cells of the 

 epidermis where they have probably migrated. 



By transmitted light this layer of droplets appears bright 

 yellow (Fig. lo A), while by reflected light it disappears almost 

 entirely, in other words it does not reflect light to any marked 

 extent (Fig. lo B). In this respect it differs from the ochrophore 

 layer of Keller, which its describer found to be bluish white by 

 reflected light. 



The sections treated with Scharlach R caused this layer to be- 

 come brownish red, indicating that the droplets composing it are 

 lipochromes. 



This layer of oil droplets is practically absent on the ventral 

 surface of the body and entirely so on the adhesive pads of the 

 feet. To what extent it is present along the mid-dorsal stripe, I 

 am unwilling to say. That it occurs here in individual lizards to 

 the same extent as on the lateral scales is true; but whether it is 

 greatly diminished in those lizards showing a white dorsal stripe, 

 or whether it is present to the same extent but can be displaced to 

 the periphery of the scale by a special mechanism and there does 

 not effect the color, it is difficult to say. Keller believes that this 

 layer can be removed from the field of action by special cells. 



One may conclude, then, that beneath the epidermis of the 

 dorso-lateral scales there is a thin layer made up of transparent 

 yellow oil droplets and that this disappears in stained preparations 

 due to its solubility in alcohol, ether and clearing oils. 



Zanihophores. — Lying just beneath the epidermis of the lat- 

 eral aspect of the body and in the oil droplet layer, are 

 cells of varying sizes. The larger cells have a clear, round, un- 

 stained cytoplasm in the sections stained with haematoxylin and 

 eosin. The nuclei are large and vesicular and the chromatic ele- 

 ments stain deeply (Figs, ii and 14). The nimiber of these cells 

 varies in the scales of the different parts of the body, being prob- 

 ably more numerous along the mid-dorsal stripe. In fresh speci- 

 mens it was practically impossible to distinguish them with accu- 



