A few cases of mimicry have been recorded in birds.
The mimicry of these insects therefore is synaposematic; but some, at all events, of the flies like the Bombylid Exoprosopa umbrosa, probably form pseudaposematic elements in the group. Into another category Hymenoptera enter not as models but as mimics, the models being inedible Malacodermatous beetles mostly belonging to the genus Lycus and characterized by orange coloration set off by a large black patch upon the posterior end of the elytra and a smaller black spot upon the thorax.
But if it be discovered, as is possible, that the drone-fly is also inedible, the mimicry must be ascribed to the Mullerian category, and the reason for it becomes less evident.
Since belief in the adequacy of the two theories, above outlined, to account for the facts they profess to explain, depends ultimately upon the testimony that can be brought forward of the usefulness of warning characters, of the deception of mimicry and of the capacity for learning by experience possessed by enemies, it is necessary to give some of the evidence that has been accumulated on these points.
The results of this experiment with the baboon and of those with the birds are precisely what would be expected if the theory of mimicry is true.