HYMENOPTERA : STRUCTURE. 373 



the collar ; and at the sides are attached the two pairs of 

 wings, the anterior pair having a scale (squamula) at the 

 base. The front margin of the anterior wings is furnished, 

 a little beyond the centre, with a callous point, termed the 

 stigma, c, from which is emitted a vein or nerve, which runs 

 to the tip of the wing, the space between it and the front 

 margin of the wings forming one or two cells, which are 

 termed the marginal or radial cells, a. Behind this nerve, 

 and running somewhat parallel with it, is another nerve con- 

 nected with the former by various short transverse nerves, 

 the space between which forms the submarginal or cubital 

 cells, b b b b, varying in number from one to four : there are 

 other nerves forming basal and discoidal cells, but the former 

 are of the greatest importance, being employed as affording 

 constant characters in the discrimination of genera. There 

 is, perhaps, nothing more strikingly calculated to prove the 

 beautiful order and certainty existing throughout nature than 

 is exhibited by these slender and apparently trivial nerves, 

 which maintain their position in every individual of a given 

 species, although in the adjacent species the situation of some 

 one or other of them may be altered. Of such importance, 

 indeed, is the consideration of these nerves, that in the 

 latest work upon the Hymenoptera, (St. Fargeau, Hist. Nat. 

 des Hymenopt., Paris, 1836) we find upwards of five-and- 

 twenty pages devoted to their illustration. We have here 



represented the anterior wing of Gorytes, in which we have 

 a number of cells ; but in some groups the number of the 



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