^5^^ 



THl-ORirS OF MIMICRY 



Another and ccjuall) iiU<r(slln<^^ niclhod is adopted by 

 certain tropical American Rhynchota llonioptera Ix^long- 

 ing to the family Mcnib) acidac. In this remarkable group 

 the dorsal region of the first thoracic segment (the pro- 

 notnm) is of enormous size, extending upwards and 

 backwartls so as completely to cover the insect with the 

 exception of the head, limbs, and wings. What Natural 



Fig. 6. 



IlG. 5. 



Fig. 5. — A Locustid from the Sudan, Myrnucophana fallax (Urunner), seen from 

 alx>ve and from the left side. < )n this insect the apjiearancc of an ant is 

 represented in black pigment, all other parts beini,' lij^ht in colour and 

 jjresumably concealed. ^^Froni lirunner von W'atlenwyl, Wrhaudl. d. k.-k. 

 tool.hoian, Gcs. in Jf'uft, lid. xxxiii, 1883, pi. xv, fi^^s. 1 a 8c \ l>.) 



Fig, 6. — A Central American Menibracid (Rhynchota Ilomoptera) in which the 

 protlioracic shield resembles an ant. Tluis the body of the insect which is 

 not like an ant is concealed by an ant like shield. The species is Jletcronotus 

 trinodosus as seen from al>ove and the left side. The upjier of the two 

 fij^ures seen from the side rejiresents a female, the two other fij^ures, males. 

 (From W. W. Fowler, Inol. Ceutr.-Afn ., A'ytu h. //o>nof>t., vol. ii, j)l. 6, fij^s. 

 16, 16 A, & 17.) 



Selection effects in the general body-form of other insects 

 must here be effected, if it is to be of any value, in the 

 shield, which is seen, and not in the body, which is 

 concealed. This chanue has been brought about, and 

 certain species of the groujj have their un-ant-like bodies 

 concealed under an ant-like shield. In other species the 



until so late a.<^ 1899 (David vSharp, F.R.S., Insec/a, vol. ii, Loiul., 1899, 

 PP- 556, 557» f'ig- 269).— E. B. P., Oct. 1906. 



