24 Journal New York Entomological Society. t^'°'- ^>^iv. 



meat of the Hymenoptera, and other studies, concludes that the 

 wings "are outgrowths of the scutal region of the notum " (or 

 tergum). He also states that "in the house fly, the wings are evi- 

 dently outgrowths of the meso- and metanotum," as shown by his 

 earlier studies of the development of these Diptera (Packard, 1874) ; 

 and further remarks that " the wings in all hemimetabolous insects 

 are outgrowths from the notum, and not from the flanks or pleurum 

 of the thorax." The numerous embryological studies of Heymons, 

 1895-1899, have clearly shown that the wings are tergal structures, 

 even in Coleoptera {Tenebrio, etc.), and Heymon's observations, 

 including as they do such diverse forms, should have considerable 

 weight, aside from his acknowledged ability as a keen observer. 

 The view that the wings are tergal structures is supported by a great 

 number of other investigators, among whom may be mentioned 

 Duerken (1907), Voss (1905), Kruger (1898), Haase (1891), Sim- 

 roth (1891), Cholodkowsky (1886), Pancritius (i884),Dohrn (1881), 

 Hofmann (1879), Mueller (1875), Huxley (1877) and others. 



As pointed out by the writer (Crampton, 1908-1914) and others 

 the posterior margin of the principal tergal plate is continued in the 

 hind border of the wing, as the so-called spring-vein, axillary cord, or 

 ligament (see Figs, i, 6 and 7, of Plate/-;-), and this fact, together 

 with the mode of development of the wings in the Blattidje and 

 other primitive insects, would indicate that the wing (or at least its 

 dorsal lamella) is tergal in nature. The wings, as we have seen, are 

 entirely homologous in all insects, so that all have a common origin, 

 and what is true of one, holds for all. The foregoing facts would 

 therefore indicate that the wings of all insects are, at least in part, of 

 a tergal nature, and the studies of Heymons (1895-1899) and others 

 cited above would substantiate the view that the wings are tergal in 

 origin ; so that for the time being, this view may be accepted as being 

 as probable as any; although subsequent investigation may show that 

 the lower lamina of the wing, or its basal portion, may be pleural in 

 nature. 



The wings, then, are organs of paranotal origin, and are wholly 

 or partially tergal in nature. In other words, they arose as paranotal 

 expansions of the tergum, although the lower lamella of the integu- 

 mentary fold forming them may be in part pleural. 



As to the articulation of the wings with the body, there are three 



