256 THEORIES OE MIMICRY 



land, Wisconsin, in July and Au<^ust, 1897. when visiting 

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

 the same flower-heads. The appearance and movements 

 of the beetles were extremely ant-like, the suc^gestion 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. TIk^ increased 

 ilarkness was in realitx' due to the shadow in tlie 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 el\ tra of the 

 beetle and the abdomen and thorax of the ant. while the 

 head of the latter was represented li\ the beetle's head 

 .md thorax together. These resemblances are indicated 

 in Eig. 4 (p. 255) ; but the living insect is ref[uired in order 

 full)- to appreciate them. 



In all the cases alluded to above, the resemblance is 

 attained b}- 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 b)- 

 which the same end is attained. One of the most inter- 

 esting of these is the case of a Locustid {^Pliaiicroptcridcs), 

 Myrmccop/iana fa/lax from the Sudan, described by 

 Hrunner von W'attenwyl.' Brunner's two figures are 

 reproduced as Eig. 5 on p. 258. Upon the stout bod)- 

 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 tlie habits of the insect nothin<»- is kncnvn. 

 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- Ikunner von Watten- 

 wyl again alludes to this example, and states that the form 

 ot the species * leads to the conclusion that it lives on the 

 ground ', viz. in the position which gives a meaning to the 



' Verhandl. der k.-k. zool.-botan. Gcs. in li'/rn. 1883. p. 247. 

 • Ohservatinns on the Coloration 0/ InsutSy Englibh tianblalion hy E. J. 

 Bits, Leipbic, 1897, p. 11. 



