2 6o THEORIES OF MIMICRY 



and legs of the insect are visible just as, in the case of 

 the ant, they appear beneath the piece of leaf which is 

 carried vertically between the mandibles and thrown over 

 the back. 1 The appearance of the Membracid and leaf- 

 carrying ant is shown in Fig. 7 (p. 259). It is probable 

 that certain species of the Orthopterous genus Tettix 

 (Acridiidae) also resemble ants carrying leaves. 



It would of course be ridiculous to ascribe this last resem- 

 blance to any direct external forces connected with locality, 

 or to any internal forces, independently producing a like 

 result, and, as the resemblance appears at an immature 

 stage, it is equally impossible to invoke the aid of Sexual 

 Selection. 



Natural Selection remains as the only feasible inter- 

 pretation. 



Even more striking than this remarkable example is 

 the contemplation of all these various methods and their 

 relation to each other. The means by which the resem- 

 blance to ants is brought about are diverse, the end 

 the resemblance itself is uniform. Furthermore, the 

 likeness is almost always detailed and remarkable, how- 

 ever it is attained, while the methods made use of differ 

 absolutely. Such a result, it would seem, is the most 

 complete proof of the operation of Natural Selection that 

 can be attained, short of the actual demonstration of its 

 action by observation and statistics. If this argument be 

 confirmed by a study and comparison of the foregoing 

 Figs, i to 7, I venture to think that it will meet with 

 general acceptance. 



When one insect resembles an ant by the superficial 

 alteration of its whole body-form, another by the modifi- 

 cation of a shield-like structure which conceals its unaltered 

 body, another by having the shape of an ant painted, as 

 it were, in black pigment upon its body while all other 

 parts are rendered invisible ; another by a further modifi- 

 cation of the body, so that it represents not an ant only, 

 but the object which the ant is almost always carrying, 

 when the effect of all these results is heightened by appro- 

 priate habits and movements, we are compelled to believe 

 1 Prof. ZooL Soc. Land., 1891, p. 462. 



