8 Journal New York Entomological Society. [Vol. xxiv, 



of the same series), but that wings are not derived from gills. He 

 goes on to show that in certain Lepismatidse there occur tergal folds 

 (well supplied with tracheae) which serve to protect the sides of the 

 thorax and the base of the legs. These lateral tergal expansions he 

 compares to the lateral folds of the carapace of Crustacea (teste 

 Henneguy, 1904), and suggests that they became transformed into 

 gills in those insects which became adapted for aquatic life, while 

 they were metamorphosed into wings in the aerial forms. 



Graber (1875) suggests that the wings of insects may have arisen 

 in two ways. Thus in the terrestrial forms (e. g.. Termites) they 

 may have been derived from tergal outgrowths, while in the aquatic 

 forms (c. g., Ephemerids) they arise as metamorphosed tracheal gills. 

 He also clearly points out that the lateral expansions of the Locustid 

 pronotuni are homodynamous with the wings. 



The foregoing views lead up to the discussion of those theories 

 in which it is maintained that the wings arose as lateral expansions 

 of, or near, the tergal region, and were not necessarily connected 

 with a respiratory function primarily. Since they are always borne 

 " alongside " of the nota, or tergal plates, for the sake of convenience, 

 in the following discussions, I would refer to these lateral folds as the 

 " paranota," regardless of whether they are entirely tergal in origin, 

 or entirely pleural, or a combination of both. The theories dealing 

 with this origin of the wings may therefore be referred to as the 

 paranotal theories. 



Among the earliest of the theories advocating a paranotal origin 

 of the wings may be mentioned the views of Mueller, 1875. From 

 his studies on the development of the wings of the Termite Calo- 

 tcrmcs, Mueller concluded that the wings did not arise from tracheal 

 gills, but from lateral tergal expansions (paranota) similar to those 

 found in the pronotum of Calotermcs, which greatly resemble the 

 wings in their mode of development. Pancritius (1884) also sup- 

 ports this view, and likewise lays stress upon the fact that the tracheae 

 enter the forming wings at a comparatively late stage in certain im- 

 mature insects — as Mueller had pointed out was the case in Calo- 

 termcs. Bugnion (1911) has also called attention to the prothoracic 

 structures of Coptotcrmcs flavus, " whose larvae bear rudiments of 

 prothoracic wings." 



The investigations of Mueller (1875) on the development of the 



