THE BUTTERFLY. 



proper, which unite with the median vein to 

 close the cell. None of the median nor any of 

 the inferior subcostal branches are ever forked ; 

 but at the apex of the front wing, where the 

 play of neuration is usually the greatest, the 

 last superior subcostal branch is occasionally 

 forked. 



The neuration of the wings, then, consists of an 

 upper and a lower (or two lower) simple straight 

 veins, and a pair of middle veins which unite 

 with or approach each other near the centre of 

 the wing ; and from the outer edge of the cell or 

 loop thus formed throw off to the border a num- 

 ber of branches. 



The wings of butterflies are very large in pro- 

 portion to the body and are subtriangular in 

 shape, particularly the front pair ; here the 

 broadest side is at the front, and is always more 

 or less convex, and closely crowded with the 

 strongest veins ; just as in a bird or a bat the 

 bones of the wings lie next the front margin, 

 where the greatest resistance is required ; in the 

 hind wings of butterflies, where no such special 

 resistance occurs, the veins are almost equally dis- 

 tributed, and the wing itself is of a more quad- 

 rangular shape, extending equally backward and 

 outward, so as to bring the middle of the plane 

 of the combined wings opposite the centre of 

 gravity of the entire body. 



