xviii Table oj Contents 



CHAPTER XXV page 

 The Wings of the Hymenoptera 



(a) The general features of the wings of the Hymenoptera 362 



{h) The venation of the wings of the more generahzed Hymenoptera 362 



(c) The tracheation of the wings of the Hymenoptera 368 



{d) Methods of modification of the primitive hymenopterous type of wing- 

 venation 370 



Reduction by atrophy 371 



Reduction by coalescence 374 



Modification of the course of a vein by the coalescence at base 375 



Modification of the course of a vein by the coalescence of its tip with an 



adjacent vein 375 



Serial veins 376 



(e) An illustration of the reduction of the wing- venation in the Hymenoptera 379 



CHAPTER XXVI 



The Teaching of the Uniform Terminology of the Wing-Veins of Insects 



Suggestions to teachers 382 



Outline of laboratory work in the study of the venation of the wings of insects 387 



Bibliography 417 



Index 424 



