A NATURALIST IN BRAZIL 



hold, Wasmann found that the legs and antennae had sometimes 

 been mutilated. Probably the beetle, while cUmbing some little 

 eminence, had fallen over on its back, and the ants, now seeing 

 the under side of its body, reaUzed that it was not so unassailable 

 as it had pretended, and snapped at its struggling limbs. 



Certain insects whose presence is dangerous are sometimes found 

 migrating in the midst of the ants. There are flies whose wingless 

 females march with the column, while the males hover above them. 

 These flies have no particular resemblance to the ants, nor are their 

 bodies protected; but they exude a fluid secretion much appreci- 

 ated by the ants, for which reason they are tolerated. This does 

 not prevent them from repaying good with evil. While an ant is 

 contentedly licking such a fly, the latter abuses its confidence by 

 calmly fastening an egg upon its body. From this a larva emerges 

 which bores into the ant's body, and proceeds to devour it in the 

 usual manner of such parasites, leaving the vital organs to the last. 

 Another fly is the Apocephalus; this is a parasite on other species 

 of ants. As a larva, it eats its way into the head of its unfortunate 

 victim, and continues to eat until the head falls off, when it lives 

 in the head as a snail Uves in its shell, so that the observer is amazed 

 to see severed heads mysteriously moving about in the midst of the 

 ants. There are also Ichneumons, which resemble the ants, being 

 wingless, and which, though they are tolerated, or even licked and 

 guarded by the ants, lay their deadly eggs in their hosts' bodies. 



The most remarkable companions of the Migratory Ants, however, 

 are those guests — for the most part Staphylinidae — which have 

 assumed the outward likeness of their hosts. Wasmann has told us 

 how perfectly this "mimicry" is adapted to the ends in view. He has 

 shown that the guests of the blind Migratory Ants resemble them 

 in form and hairiness — that is, in peculiarities which the ants can 

 recognize by touch — whereas in the company of the "sighted'* 

 Drivers they adopt a "visual mimicry," inasmuch as they resemble 

 their hosts chiefly in respect of their colour. Even among the Ich- 

 neumons of which I have spoken there is one species, the Mimopeia, 

 which in shape and colour exactly resembles the sm.allest of the 

 reddish-brown workers of one of the Migratory Ants — which can 

 both see and feel. Another species, which lives with one of the blind 

 Migratory Ants, has actually adopted the form of these ants, the 

 abdomen being attached by a stalk, though its colour is quite 

 different. 



But the supreme examples of mimicry are found among the 

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