Vol. 1.] Woodwort]i. — W ing Veins of hisects. 3 



subject from the standpoint of comparative anatomy, the aim 

 being to establish a sound nomenclature. Among these are 

 Adolph, Amans, Brauer, Comstock, Needham, and Redten- 

 bacher. 



The result of all this work is that there has been a more 

 exhaustive study of the wings than of any other part of the 

 insect's anatomy. Thousands of species, representing every 

 group of any importance, have been illustrated. The details 

 of the subject can be said to have l^een very fully worked out, 

 but on the theoretical side not much progress has l)een made. 

 Most of the theories that have been proposed have been of 

 limited application, relating generally to small matters of 

 special adaptations. 



What most needs to be done is to develop a general theory 

 of venation that will serve in the interpretation of the facts 

 that have been so richly accumulated. The present work is 

 an attempt in this direction. The studies of the author have 

 been under way since 1884, and have included the study of 

 microscopical preparations of the wings of about two thousand 

 species representing all the principal groups, the examination 

 of a much larger series of insects with spread wings, and the 

 inspection of practically all the published figures of insect 

 wings. Representatives of most of the larger groups have 

 been studied in their earlier stages, both from simple micro- 

 scopical preparations of wingpads and from sections. It will 

 not be useful to attempt to present the mass of material thus 

 accumulated, as much of it would of necessity be but the 

 verification of work already well done by others, or the criti- 

 cism of relatively insignificant details. 



The author desires to acknowledge the inspiration and 

 encouragement of Professors Burrill and Forbes of the Uni- 

 versity of Illinois, with whom his first work on this subject 

 was begun, and the invaluable assistance and advice of that 

 honored and lamented prince of entomologists, Dr. Hagen, 

 whose invariable kindness during the two years' work in his 

 laboratory can never be forgotten; to Dr. Mark, with Avhom 

 the concluding work has been done, his indebtedness is fully 

 as great; to numerous entomologists, who have aided him with 

 material, and to his students and assistants, especially for the 

 making of preparations, his thanks are due; he regrets that 

 he can not mention them all by name. 



