SOME INSECT ADAPTATIONS 31 



as that of the relation between the milkweed butterfly and its 

 near relative the viceroy butterfly. The milkweed butterfly 

 seems to be inedible to birds and is warningly colored. Its 

 cousin, the viceroy, which is eaten by birds, resembles the 

 milkweed butterfly so closely that one must examine the two 

 with care to distinguish one from the other. The viceroy is 

 supposed to mimic its larger relative and thus escape by being 

 mistaken for its inedible model. 



Sometimes the colors of an animal are not only protective but 

 aggressive, since they effectively conceal their owner while it is 

 creeping upon its prey. A green snake among green leaves can 

 thus get close to its victim without being seen. No sure cases of 

 aggressive coloration are known among insects. 



REFERENCES 



Entomology, by J. W. Folsom. — P. Blakiston's Son and Co., Philadelphia. 

 Textbook of Entomology, by A. S. Packard. — The Macmillan Co., N. Y. 

 City. 



