336 



THE WINGS OF LEPIDOPTERA 



from trachea r-m. In the fore wing (Fig. 333) trachea Mi has reached the 

 radial trachea and coalesces with it for a considerable distance. If this 



Ki R 



2d A 



Fig. 344. — Tracheation of a fore wing of Anosia. 



coalescence were to continue to the margin of the wing, vein Mi would be 



lost as completely as is vein M4. 



From these facts I conclude that in both fore and hind wings trachea M4 



has reached trachea Cui and has 

 coalesced with it completely. In 

 other words the reduction of media 

 is the result of the coalescence of 

 veins M4 and Cur, hence the vein 

 that is commonly designated as Cui 

 in the Lepidoptera is really vein 

 M4+CU1. 



In the fore wing of Pier is rap(S 

 (Fig. 333), the vestige of the secon- 

 dary connection between the medial 

 and the radial trachea has been lost, 

 although that between the medial 

 and cubital tracheae has been 

 retained. Both of the vestiges are 

 commonly lost ; but one or both of 

 them are retained in many lepidop- 

 terous pupae. That between the 

 medial and cubital tracheae is well- 

 Fig. 345. — Wings of Citheronia regalis. preserved in the pupa of Anosia for 



example (Fig. 344). 

 Although I firmly believe that the vein in lepidopterous wings that is 



commonly designated as vein Cui is really vein M4+CU1, for the sake of 



simplicity, it seems better to designate it ordinarily as vein Cui. This is in 



