MIMICRY IN SPIDERS. 363 



a peculiar whistle, which was at once recognized by the flock of chickens, 

 who hurried together at the call, as tame birds always do when summoned 

 to feed. The gamekeeper tossed them several bits of sod containing ant 

 nests, which the birds attacked, tore in })ieces, and in a moment had de- 

 voured all the insect contents. Simonella americana is not nuicli larger 

 than these ants, and certainly there would be little protection from such 

 voracious creatures as these in the mimicry of ant forms. I have no doubt, 

 although I cannot speak positively, that our American quail are equally as 

 fond of ants as these English partridges ; and as they are ground birds, 

 their habits of feeding would make them destructive enemies of all ant spe- 

 cies burrowing in the earth. 



Again, it is well known that in the warm districts of South America, 

 and in other parts of the earth, there is a family of birds who are such 

 persistent destroyers of ants that they take their family name 

 p-^^-j from this habit, and are known as the Formicariida'. ^ These 

 ant thrushes, Pittas or Pittidte, are also an Old World group, 

 being found in the Malay Islands. The Great ant thrush, which is also 

 called the Giant Pitta, is a native of Surinam, and is a bird about the size 

 of the English rook.^ 



I have heard, although I cannot now cite the authority, that in Africa, 

 when the Driver ants go out upon their excursions, during which they will 

 prey upon all sorts of insects and small vertebrate animals, ant thrushes, 

 or some species of ant devouring bird, hover over the raiding column, 

 u2)on which they make their assaults, devouring immense numbers of the 

 drivers.^ Such are some of the facts which have fallen to my notice, or 

 under my eye ; and while it is probably true that some birds avoid ants 

 as articles of food, I imagine that nearly all animal feeding birds will pick 

 them up whenever they have an ojiportunity. Such being the case, we can 

 hardly admit the force of an argument which is based upon the supposi- 

 tion tluit the form of an ant would i)rotect a spider, or any other creature, 

 on account of the disrelish of birds for ants. 



If we were inclined to accept the theory of natural selection, as above 

 outlined, as an origin for mimicry of ant forms, it would seem to me more 

 rational to suppose that the particular enemy against which the 

 ■^^^ mocking form is protected, is not the bird, but the wasp and 



asps ichneumon fly. My chapter on the Enemies of Spiders shows 

 icked? what depredation is wrought among araneads by various mem- 

 bers of the wasp family. As far as I know, wasps do not inter- 

 fere with each other, or with ants, who closely resemble them, being, in 

 fact, members of the same order of Hymenoptera. Anything that would 



'Alfred Wallace, "Geographical Distriliution of Animals, Vol. II., page 29(3; 'Wright, 

 "Aniirial Life," page 271. - "Wood's Natural History," page 341. 



^ I think that this, or a similar fact, was told me by an African missionary to the Congo 

 region. 



