222 ' JouKNAL New York Entomological Society. [Voi. xi. 



boldly declares its owner, inviting attention and daring and braving 

 attack and capture. Such colorati'on by way of distinction may be 

 termed "aggressive or hostile" as opposed to passive where the 

 colors copy and blend with surrounding objects, the terms "aggres- 

 sive" and "passive" being understood to be merely relative and 

 to imply no special consciousness or instinct. It would seem a fair 

 question to ask what environment or circumstance of natural selec- 

 tion could have produced a decoration so variant and which must 

 necessarily have been acquired under substantially the same conditions 

 as that of other noctuids. Although North America is virtually the 

 home of the Catocala, species of this genus, or at least species having 

 a similar scheme or plan of maculation occur almost universally, among 

 which may be mentioned the Ophiderides of India and Java, while 

 hosts of unrelated genera also possess lower wings far more attractive 

 and conspicuous than the upper, and, therefore, whatever theory may 

 be offered in explanation of this characteristic in the Catocala would 

 apparently apply equally to the others. Since the problem of the 

 origin of aggressive coloration does not appear at first glance to be 

 directly demonstrable, a more satisfactory method of solution may be 

 obtained indirectly by considering the circumstances under which 

 certain forms of the secondaries have been developed and the uses to 

 which they are applied, since, however remarkable the contrast of 

 hues between the upper and lower wings, it is not more peculiar and 

 surprising than the apparently abnormal secondaries of many other 

 groups of lepidoptera to which tails are attached, moderately among 

 the papilios, graptas, theclas, certain hesperians and many others, or 

 extraordinarily, as in the case of Actias liina and allied species. The 

 theory has been advanced and it seems quite a reasonable one that 

 development by prolongation of the lower wings in the form of tails, 

 abnormal and apparently unnecessary as it is, is really a factor of 

 high value as a means of preservation of an insect from destruction by 

 its enemies. Again and again may predatory bat or bird, in an effort 

 to capture a moth or butterfly, successively tear away sections of the 

 tails, of which a sacrifice can be readily afforded, without disabling it 

 or retarding its flight. 



The abnormal development of these appendages or tails seems to 

 have originated from the fact that whenever, in the course of natural 

 variation, certain individuals have been congenitally provided with 

 secondaries unduly enlarged, these individuals by reason of being pos- 



