THE BUTTERFLY. 



71 



and, when present; internal. The costal, subme- 

 dian, and internal veins are invariably simple 

 and terminate at the 

 margin or even disap- 

 pear before reaching 

 it. The subcostal and 

 median veins, on the 

 other hand, are as 

 invariably branched, 

 and with their off- 

 shoots support nearly 

 the entire wing [Fig. 

 75] ; the subcostal 

 vein curves downward 

 and the median up- 

 ward so as to meet, 



or nearly meet, about the middle of the wing, and 

 to inclose between them a large space called the 

 discoidal cell ; all the branches of the median vein 

 are thrown off from its lower side 

 before union with the subcostal vein ; 

 the principal branches of the sub- 

 costal vein, on the other hand, are 

 thrown off from its upper side [Pig. 

 76] ; but as the vein curves down- 

 ward at the extremity of the cell, 

 another set is thrown off, at least in 

 the front wings, from the lower side ; and it is 

 these branches, rather than the subcostal vein 



FIG. 75. Veins of the wing in Laertias 

 Philenor, nat. size. 



Fio. 76. Veins 

 of the wing in 

 Euphyes M e t a - 

 comet, nat. size. 



