No. 380. ] THE WINGS OF INSECTS. 565 
With this we conclude our discussion of the venation of the 
series of forms illustrating the specialization of wings by reduc- 
tion. The sequence in which the forms have been discussed 
has been determined merely by convenience, except that we 
believe that the Plecoptera, which were treated first, resemble 
the primitive winged insect in the tracheation of their wings 
more closely than do the members of any other order as a 
whole. In the next chapter we will give some illustrations of 
the specialization of wings by addition. 
ENTOMOLOGICAL LABORATORY, 
CORNELL UNIVERSITY, May, 1898. 
