n these cases the creature is almost without smell or taste. This, Dr.
Ogle believes, explains the curious case of the pigs in Virginia adduced
by Mr. Darwin, white pigs being poisoned by a poisonous root, which does
not affect black pigs. Mr. Darwin imputed this to a constitutional
difference accompanying the dark color, which rendered what was
poisonous to the white-colored animals quite innocuous to the black. Dr.
Ogle, however, observes, that there is no proof that the black pigs eat
the root, and he believes the more probable explanation to be that it
is distasteful to them, while the white pigs, being deficient in smell
and taste, eat it, and are killed. Analogous facts occur in several
distinct families. White sheep are killed in the Tarentino by eating
Hypericum Criscum, while black sheep escape: white rhinoceroses are said
to perish from eating Euphorbia Candelabrum; and white horses are said
to suffer from poisonous food, where colored ones escape. Now it is very
improbable that a constitutional immunity from poisoning by so many
distinct plants should in the case of such widely different animals be
always correlated with the same difference of color; but the facts are
readily understood if the senses of smell and taste are dependent on the
presence of a pigment which is deficient in wholly white animals. The
explanation has, however, been carried a step further, by experiments
showing that the absorption of odors by dead matter, such as clothing,
is greatly affected by color, black being the most powerful absorbent,
then blue, red, yellow, and lastly white. We have here a physical cause
for the sense inferiority of totally white animals which may account for
their rarity in nature. For few, if any, wild animals are wholly white.
The head, the face, or at least the muzzle or the nose, are generally
black. The ears and eyes are also often black; and there is reason to
believe that dark pigment is essential to good hearing, as it certainly
is to perfect vision. We can therefore understand why white cats with
blue eyes are so often deaf; a peculiarity we notice more readily than
their deficiency of smell or taste.

If then the prevalence of white-coloration is generally accompanied with
some deficiency in the acuteness of the most important senses, this
color becomes doubly dangerous, for it not only renders its possessor
more conspicuous to its enemies, but at the same time makes it less
ready in detecting the pr