226 Journal New York Entomological Society. [Voi. xi. 



analogy I should prefer the latter, and for this form of protective de- 

 velopment I would coin a third term "aggressive maculation." 



We have then six terms to express protective development, viz., 

 passive or negative formation, maculation and coloration, and active, 

 aggressive or hostile formation, maculation and coloration. For prac- 

 tical application of these terms we may confine ourselves to the lepi- 

 doptera. Among the noctuids in general, omitting the genus Caiocala 

 the entire family depends for concealment upon the two last divisions 

 of the first class, viz., passive or negative coloration and maculation, 

 while certain of the graptas by folding their wings with deeply 

 indented margins furnish examples of all three divisions. Moths like 

 the Acfias, as our native luna, furnish examples of both passive colora- 

 tion (in that the wings are of a delicate green shaded with white 

 resembling many large leaves) while the projection rearward of its 

 secondaries furnishes an example of aggressive formation, being thus 

 doubly protected whether at rest or in flight. The Catocala are also 

 doubly protected, but in a different way, the fore wings furnishing 

 examples of passive coloration and maculation while the hind wings 

 are models of aggressive coloration except in cases where they are em- 

 ployed under circumstancss above named to blend with the alternate 

 shadings of grass stalks and other herbage. The aggressive formation 

 of the luna is for protection during flight while the aggressive colora- 

 tion of the Catocala is principally for protection while at rest. It 

 would be an interesting as well as an instructive exercise to examine 

 the wing structure, coloration and maculation of numerous species and 

 endeavor, in connection with such knowledge as can be gained con- 

 cerning their life-histories, to trace the causes which probably pro- 

 duced the variations of each, in accordance with the classification 

 above prescribed, taking into consideration nevertheless that all deduc- 

 tions are necessarily limited to such meager inference and knowledge 

 as we may chance to possess of the varying environments to which 

 previous generations have been subjected through myriads of ages. It 

 must also be conceded that no result has been without object, but that 

 every form with its accompanying shades and patterns of color has 

 been evolved for a definite purpose in the course of the pitiless struggle 

 for existence since the beginning, and remains more or less permanent 

 though the circumstance which promoted its origin may have long 

 since passed away. 



