the ant, or whether it is merely protective. It may be that
the spider, by virtue of its resemblance to the ant, not only gets an
abundant supply of food, but also escapes being eaten itself, and thus
enjoys a double advantage. Both Bates and Wallace take the ground that
the advantage derived by the spider consists in greater ease in the
capture of prey, but both of these writers refer to spiders only
incidentally to illustrate a general proposition, without special
consideration of their peculiar conditions.

Mr. Herbert Smith, who has paid a good deal of attention to this
subject, is inclined to believe that the mimicry in question is
entirely protective. He writes as follows:--

"In the United States there are a few rare spiders that mimic ants.
Here at Taperinha we find a good score of species of these spiders
aping the various kinds of ants very closely; even the odd, spiny
wood-ant, _cryptocerus_, furnishes a pattern, and there are spiders
that mimic the wingless ichneumons. We find, after a while, that the
spiders prey upon ants just as our spiders catch flies; indeed, this
fact has already been noted by other observers. But we go a step
beyond the books when we discover not only that the spiders eat the
ants, but that they eat the particular ants which they mimic. At all
events, we verify this fact in a great number of cases, and we never
find the spiders eating any but the mimicked species.... I do not like
to hazard a theory on this case of mimicry. It is difficult to suppose
that the quick-witted ants would be deceived even by so close a
resemblance; and, in any case, it would seem that the spiders do not
require such a disguise in order to capture slow-moving ants. Most
birds will not eat ants; it seems likely, therefore, that this is
simply another example of protection; the spider deceives its enemies,
not its prey; it mimics the particular species that it feeds on,
because it is seen in that company when it is hunting, and among a
host of similar forms is likely to pass unnoticed."

At first sight, and especially in view of the fact that such cases are
not uncommon among insects, it would be naturally supposed that the
object of the mimicry was to enable the spider to approach its victim
without exciting suspicion; and it is difficult to account, on any
other supposition, for the very close resemblance between certain
species of spiders and the particular species of ants which they prey
upon. It seems