2 Journal New York Entomological Society. t^'°'- -^^^v. 



of insects as new structures, although he is not so outspoken in the 

 matter as Audouin (1824) and Lacordaire (1834), who regard in- 

 sects' wings as organs " sui generis." Lacordaire in particular, seems 

 to regard further discussion of the subject as unprofitable, in view of 

 the fact that, since the wings are (as he thinks) entirely new organs, 

 they can have no relation to any previously existing structures. 



It is possible that Audouin and Lacordaire are correct in their 

 contention that the wings are organs "sui generis" although they 

 were doubtless influenced in their belief by the then prevalent idea 

 of " special creation," whose adherents maintained that each species 

 (and hence the organs peculiar to it) was created quite independently 

 of other organisms, and consequently the idea of structures arising 

 as modifications of preexisting structures, was precluded by the very 

 nature of the hypothesis. In accordance with the modern conception 

 of the method and factors of evolution, however, it is difficult to con- 

 ceive how wings of sufficient size and development to be of any use 

 to the organism could have arisen, save through the predominance of 

 some new function, or use, in organs which had some prior function 

 or significance. 



It is not always necessary, however, to suppose that the preexist- 

 ing structures originally served any useful purpose, since an inherent 

 tendency toward the greater development of certain structures (pro- 

 jections of the body-wall, etc.) might find opportunity for fuller ex- 

 pression, so long as such a development did not lead to a condition 

 detrimental to the organism — in which case natural selection would 

 operate to prohibit further progress along this line, while the per- 

 sistence of such structures would be assured, if they reached a stage 

 wherein they were capable of furnishing their possessors with a 

 means of successfully coping with their competitors or enemies, or 

 would be of assistance in maintaining the life of the organism. The 

 latter view would seem to be more in accord with our present knowl- 

 edge of the method of evolution, and is therefore more acceptable 

 than the view that the wings are organs " sui generis." 



The theories contained in the second group (in which it is main- 

 tained the wings have developed from preexisting structures) are of 

 several types. Thus, the adherents of one theory would derive the 

 wings of insects from the " elytron "-like appendages, or the gills, of 

 Annelidan ancestors; others regard the wings as modified legs, or 



