MIMICRY. 445 



universal in the Pieridce, are apparently confined to this group 

 among the Khopalocera. This fact enables the interesting 

 observation to be made, that where a Pierid mimics an insect 

 belonging to another family, the pigments in the two cases are 

 chemically quite distinct. This is well seen in the genera 

 Leptalis and Mechanitis respectively."* The experiments and 

 conclusions of Dr. McNunn and Miss Newbigin in relation to the 

 green pigments in Invertebrates have already been referred to in 

 these pages (ante, p. 430). 



The leaf-like Phasmid (cf. ante, p. 303) observed by Mr Belt 

 standing immovable among a host of foraging ants, many of which 

 ran over its legs without discovery that food was within their 

 reach.f (This may also be taken as an illustration of " Active 

 Mimicry," referred to subsequently.) 



The larvae of Geometrid Moths, which so resemble the twigs 

 on which they rest as to deceive their enemies. Rosel's gardener, 

 mistaking one of these caterpillars for a dead twig, started back 

 in great alarm when, upon attempting to break it off, he found it 

 was a living animal. t Burmeister was similarly deceived by the 

 larva of Ph. quercinaria, Borkh. (Eunomus erosaria, Tr.), "mis- 

 taking it for a small dry twig upon wishing to break off a small 

 twig of oak."§ Mr. Jenner Weir writes : — " After being thirty 

 years an entomologist, I was deceived myself, and took out my 

 pruning-seissors to cut from a plum-tree a spur which I thought 

 I had overlooked. This turned out to be the larva of a Geometer 

 two inches long. I showed it to several members of my family, 

 and defined a space of four inches in which it was to be seen, but 

 none of them could perceive that it was a caterpillar." || 



In plants, Matricaria chamomilla is considered a mimic of the 

 true Chamomile, which from its bitterness is not eaten by quadru- 



* ' Proc. Roy. Soc' lvii. pp. 5 and 6 (1894). 



f ' The Naturalist in Nicaragua,' p. 19. — Prof. S. D. Judd, who has made 

 a special study of the subject, records an observation to be remembered : — 

 " I am surprised to find that Grasshoppers (Acrididce and Locustidce), in 

 spite of their protective coloration, are eaten by over three hundred species 

 of birds in the United States." (' Amer. Nat.' vol. xxxiii. p. 468.) 



I Eos. i. v. 27. Quoted by Kirby and Spence. ' Introd. Entomol.' 7th 

 edit. p. 413. 



§ ' Manual of Entomology,' Shuckard's transl. p. 505. 



|| ' Nature,' vol. hi. p. 166. 



