VOL. I.] Colors of West Coast Mammals. 215 
made to explain all, are very alluring, but are apt to be superficial 
from their very simplicity. 
The skunks were excluded from the class of animals having colors 
for purposes of recognition. True the marked contrast of black 
and white is decidedly conspicuous. In the dark, particularly, 
‘they are the most conspicuous colors which could be devised; but 
note the very radical difference in their use from any recognition 
markings. Recognition markings are of use, not to the ones possess- 
ing them, but to their fellows; the markings of the skunk are of use 
to the individual as a warning for other animals to avoid it. 
A large number of our mammals have colors probably not very 
different from their primitive hue.. Wallace has shown that color 
is anormal product of organization. He says:* ‘‘ If we consider 
that in order to produce white all the rays which fall upon an object 
must be reflected in nearly the same proportions as they exist in 
solar light—whereas, if rays of any one or more kinds are absorbed 
or neutralized, the resultant reflected light will be colored; and 
that this color may be infinitely varied according to the proportions 
in which different rays are reflected or absorbed—we should expect 
that white would be, as it really is, comparatively rare and excep- 
tional in nature.’’ ‘‘ Now the various brown, earthy, ashy, and 
other neutral tints are those which would be most easily produced, 
because they are due to an irregular mixture of many kinds of 
rays.’’+ It is these neutral tints which are predominant among 
mammals, and in many cases they would seem to require no further 
explanation. Color does not seem to enter into the life of our 
smaller rodents, or of bats, for instance. Being nocturnal in their 
- habits their sense of sight has probably but little capacity to dis- 
-tinguish between different colors, and their habits are such that no 
very accurate protective shades are required, other than some dull 
neutral tint. Certain species which may sometimes move about on 
the desert by day, as Dipodomys, assume a color on the back 
almost identical with the sand, and with a white superciliary stripe 
_ for a recognition mark, but such forms are the exception rather than 
_ the rule. It seems highly probable that the absence of conspicuous 
. colors among mammals as a class is to be explained by the lack of 
-*Natural eictica new ed., p. 359. 
ae C., pp. 360-361. 
