On Pronuha Yuccasella. 151 



I have alluded above to the contrast between the ornamentation of 

 the species above named, and that of the flowers which they frequent; 

 but I do not wish to be understood as taking the position that there is 

 no such thing as protective resemblance (the word mimicry seems ob- 

 jectionable) among insects. Every field entomologist knows that in- 

 stances are common when the resemblance of an insect to its surround- 

 ings must in some degree protect it from its enemies, provided it has 

 enemies of such kind as to make it need such protection, and provided 

 those enemies have no better means of detecting its presence than poor 

 human eyes afford, even when disciplined by 3'ears of habit and prac- 

 tice. Neither do I want to place myself in opposition to such natural- 

 ists as Wallace, Bates, Belt, Trimen, and a host of lesser lights who ad- 

 vocate some phase or other of a protective theor}^ as connected with the 

 evolution of species. It will not do, however, to assume because there is 

 resemblance that there is necessarily protection from enemies in an}- 

 given case, unless we know what the enemy is, and that the protec- 

 tion is necessary-, and just how the resemblance operates to protect the 

 species; and. we have no reason to suppose that the species under dis- 

 cussion have any enem}^ from which they derive protection, either by 

 their residence in yucca flowers, or by their resemblance to Pronuha 

 yuccasella. It is a rash assumption that they frequent the flowers for 

 protection, since there is no evidence that they have any enemy from 

 which such protection is necessar}^; and since, if there is such an enem}-, 

 they would be exposed freely to its depredations; if they have the lar- 

 val habits of Hypononieuta on the first emergence of the imago from its 

 pupa skin, in its web, in the wooded country, before it betakes itself 

 to the pliins and the yucca for protection; and, again, on its return to 

 oviposit there. It must be a remarkable development of instinct which 

 teaches a Hijponomeuta to forsake en masse the locality where the fe- 

 male oviposits, and the larva feeds, and betake itself to another habitat 

 because it is white, and the flowers are white. Indeed, I find it diffi- 

 cult to believe that this species can have the larval habits of Hypono- 

 meuta; and equally difficult to believe that a Hyponomeuta can diff'er 

 so widel}' in habit and habitat from all other species of the genus for 

 the sake of protection, or for any other reason. Beside, I find nothing 

 in the natural history of Tineina to support any phase of a theory of 

 mimicr}^ or protection resemblance, whatever may be found in any 

 other group of animals. Some dark-colored, nocturnal species, which 

 hide in out-of-the-way places in jdaylight, may, thereb}^, escape some 

 enemies, to fall perhaps into the jaws of others which love darkness like 

 themselves. But gi-eat numbers of them are brilliant, gaily-colored lit- 

 tle creatures, loving the sun light, resting upon palings, walls, trees and 

 leaves, as if they sought to display their gay colors by the contrast. 



