166 
JOURNAL OF MAMMALOGY 
there be a genetic complex of color determiners present in the mole, 
as has been demonstrated for various rodents, it can not be seen that 
they affect different granules. The commingling must be ultramicro- 
scopic. 
STUDY OF THE XANTHIC SPECIMEN 
The aberrant specimen that precipitated this discussion shows no 
departure from the normal beyond that of the color areas of the hair. 
Palms, soles, claws, and the nearly naked skin of the tail and the nose 
are, like those of the normal animal, practically without pigment and I 
can distinguish no difference between the two color phases in respect 
to the coloration of these parts. In preparing the skin, the eye rudi- 
ments were visible and there was noticed no difference between them and 
the rudiments in normal moles. Unfortunately no microscopic ex- 
amination of these parts was made, so we lack proof for the assumption 
that the eye color was normal. 
Microscopic study of the hair shows no divergence from the normal 
except in the matter of color of the pigment. The color areas are pres- 
ent and they in every other respect correspond with those of normal 
moles, but they are light brownish yellow instead of dense black in 
tone. They are readily marked off from the adjacent spaces and from 
the colorless cortex. The same styliform effect occurs where the 
medulla is constricted. Altogether, there is no reason for considering 
the specimen as an albino in which the whole machinery of pigmentation 
is lacking. 
Whatever the theory of pigmentation toward which one may lean, 
it seems to me that this specimen represents the result of a factor 
dropped out, a chemical radical split off, a poverty in tyrosinase, or 
what you will, and that it serves somewhat to prove the complexity 
of color in a seemingly simple monochrome species of mammal. 
Southern Branch Univ, of California, Los Angeles, Calif. 
