592 PEor. E. B. poulton: natueal sEi-ECTioiir 



due to the sliadow in the depression combined with the effect of 

 a difference in the texture of the surface. This combination of 

 characters produced a strong superficial resemlDlance between 

 the elytra of the beetle and the abdomen and thorax of the ant, 

 while the head of the latter was represented by the beetle's bead 

 and thorax together. These resemblances are indicated in fig. 4 ; 

 but the liviug insect is required in order to recognize them 

 fully. 



In all the cases alluded to above, the resemblance is attained 

 by a modification in the form of body and limbs, accompanied 

 by changes in those more deep-seated structures which affect 

 the habits and movements. 



There are, however, other very different means by which the 

 same end is attained. One of the most interesting of these is the 

 case of a Locustid (Phaneropferides), Mynnecophana fallax from 

 the Sudan, described by Brunner von Wattenwyl (VerhandJ. 

 der k.-k. zool.-botan. Gres. in Wien, 188.S, p. 247). This insect 

 was erroneously described as an Acridiau in my paper before 

 the British Association at Toronto (Eeport, 1897, p. 69.3, 1. 3). 

 Brunner's two figures are reproduced as the adjacent fig. 5. 

 Upon the stout body of this insect the slender-waisted form of 

 an ant is represented in black pigment, the remainder of tlie 

 body being light in colour and probably invisible against a 

 similar background. Of the habits of the insect nothing is 

 known, but the method ia of great interest, being so entirely 

 different from that adopted by any other insect as yet described. 

 In a more recent work (' Observations on the Coloration of 

 Insects,' English translation by E. J. Bles, Leipsic, 1897, p. 11), 

 Brunner von Wattenwyl again alludes to this example, and states 

 that the form of the species " leads to the conclusion that it 

 lives on the ground," viz. in the position which gives a meaning to 

 the resemblance. In spite ot this he asks, "Is this imitation an 

 accidental freak of nature?" If Myrmecophana were the only 

 example of such resemblance the question might fairly be asked, 

 but in view of the numerous other equally close resemblances to 

 ants, produced in various ways, it is quite unnecessary. The 

 suggestion of an " accidental freak " can never explain such close 

 likeness, in appearance, in movements and habits (so far as they 

 are known), in locality — a likeness, furthermore, not to any 

 insect in the environment, but to insects of a specially successful 

 and aggressive group — a likeness not produced in one way but 



