THE STATE ENTOMOLOGIST. 159 



Described from 6 $,1^, bred from larvae of Limenitis disippus, 3 g bred from larvae of Ge- 

 Icchia cjallasolidayinis. In the latter the nervures of wings are paler and less distinct than in the 

 former. Most of our N. A. species of this genus have been described by Mr. Cressonwho has seen 

 this and considers it new. It certainly differs from the other described species. 



MIMICRY AS ILLUSTRATED BY THESE TWO BUTTERFLIES, WITH SOME REMARKS 

 ON THE THEORY OP NATURAL SELECTION. 



The means by which animals are enabled to escape from their 

 enemies and obtain their food, or in other words to sustain them- 

 selves in the great struggle for existence that is continually going on 

 between each species, are as varied as they are wonderful. There is 

 generally a conformity of tint between all animals and their surround- 

 ing, and in the higher classes Mr. A. K Wallace has shown* that in 

 general terms it may be stated that desert animals are desert colored 

 arctic animals white, and nocturnal animals gray, i. e., of such colors 

 as best to accord with the surroundings. Animals, birds, fishes and 

 reptiles come under this rule to a great extent, and the reader will be 

 amply rewarded by perusing the details given in the valuable and 

 interesting work referred to. But in no Class of animals does this 

 principle of adaptation to environment occur so generally and in such a 

 striking manner as in insects. With them mimicry and other protec- 

 tive resemblances are almost universal, and it may be given as a rule 

 that all insects living above ground, when not naturally protected by 

 odor, luminosity or defensive covering such as hairs, spines, hard 

 shelly wings, etc., or by armor such as stings, beaks, etc., either 

 cover themselves with one substance or another, or similate their sur- 

 roundings, or mimic either other animals, plants, or even inorganic 

 substances. With insects in their larval states, will this rule especi- 

 ally hold good. 



What entomologist has not been deceived by the close resemblance 

 of the beetles belonging to the genus Chlamys to the dung of cater- 

 pillars; or is not familiar with the quaint and close resemblance of 

 the Walking-sticks and Walking-leaves to the objects from which they 

 take their names ? Chapter after chapter might be written on these 

 wonderful imitations which deceive the best trained eyes ; and there 

 are many most striking instances among our American insects which 

 have never yet been published and which I hope some day to illus- 

 trate. But my present purpose is simply to draw attention to the 

 illustration afforded by the two butterflies which we have been con- 

 sidering. 



These striking resemblances were formerly looked upon, for the 

 most part, as curious analogies in nature, intended to carry out the 



-Contributions to the Theory of Natural Selection. 



