CHAPTER XXVI 



THE TEACHING OF THE UNIFORM TERMINOLOGY OF THE WING-VEINS 



OF INSECTS 



SUGGESTIONS TO TEACHERS 



Much use is now made in systematic entomology of the characters 

 presented by the wing-veins of insects. It is important, for this reason, 

 that the student should acquire, early in his study of insects, a clear knowl- 

 edge of the fundamental type of wing- venation, of the ways in which this 

 type has been modified in the different orders of insects, and of the uniform 

 terminology used in describing the wing-veins. 



The following outline of a course of study in this field is offered in the 

 hope that it may be of service to teachers ; it is based on an outline that has 

 been in use in the entomological laboratory of Cornell University for many 

 years, where the work indicated in it has formed a part of the introductory 

 courses in entomology. 



These courses have been planned to meet the needs of two classes of 

 students: first, those students who are specializing in entomology; and 

 second, those students who take only a general lecture course and the 

 accompanying practicmns in this subject. 



The students who are specializing in entomology are furnished mounted 

 specimens of the wings to be studied whenever it is practicable to do so, and 

 are required to make drawings of them representing the wing- venation. 

 In those cases where wings are not available for use in the laboratory, 

 figures of the wings in which the veins are not lettered are furnished. In 

 either case the student determines the homologies of the wing-veins and 

 records his conclusions by lettering the veins in his figures. Each figure is 

 criticised by the instnictor before another wing or figure is issued for study. 

 This is of prime importance; for without such criticism an error made in 

 one figure is likely to be repeated in the next, and an incoiTcct conclusion 

 becomes established in the mind of the student. 



The course outlined here is merely an introductory course in which the 

 student becomes grounded in the fundamental principles of the study of 

 wing- venation. The wings to be studied in it have been selected with a 

 view to illustrate the various ways in which the primitive type of wing- 

 venation has been modified in the course of the evolution of recent forms. 



This course of study, or one of similar scope, should be completed before 

 the student is encouraged to undertake an investigation of the wing-venation 

 of a particular group of insects, as a family or an order; he should be 

 impressed with the fact that the interpretation of venational characters 

 must be based upon a knowledge of the various ways in which the wing- 



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