256 THEORIES OF MIMICRY 



land, Wisconsin, in July and August, 1897, when visiting 

 Dr. C. A. Leuthstrom. Ants were also very common on 

 the same flower-heads. The appearance and movements 

 of the beetles were extremely ant-like, the suggestion of 

 a stalked abdomen being conveyed by an oblique white 

 line crossing the elytra in a very shallow depression in 

 which the dark ground-colour of the insect appeared to 

 be of a more intense black than elsewhere. The increased 

 darkness was in reality due to the shadow in the depres- 

 sion combined with the effect of a difference in the texture 

 of the surface. This combination of characters produced 

 a strong superficial resemblance 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 head 

 and thorax together. These resemblances are indicated 

 in Fig. 4 (p. 255) ; but the living insect is required in order 

 fully to appreciate them. 



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 inter- 

 esting of these is the case of a Locustid (Phaneropterides), 

 Myrmecophana fallax from the Sudan, described by 

 Brunner von Wattenwyl. 1 Brunner's two figures are 

 reproduced as Fig. 5 on p. 258. Upon the stout body 

 of this insect the slender-waisted form of an ant is repre- 

 sented in black pigment, the remainder of the body being 

 light in colour and presumably invisible against a similar 

 background. Of the habits of the insect nothing is known, 

 but the method is of great interest, being so entirely 

 different from that by which mimetic likeness is usually 

 effected. In a more recent work 2 Brunner von Watten- 

 wyl 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 



1 Verhandl. dcr k.-k. zool.-botan. Ges. in Wiett, 1883, p. 247. 



2 Observations on the Coloration of Insects, English translation by E. J. 

 Bles, Leipsic, 1897, p. 11. 



