THE WINGS OF INSECTS. 
J. N. COMSTOCK anp J. G. NEEDHAM. 
CHAPTER IV (Concluded). 
The Specialization of Wings by Addition. 
V. THE TRACHEATION OF THE WINGS OF ORTHOPTERA. 
Tue study of the tracheation of wings of orthopterous 
nymphs was undertaken merely for the purpose of determining 
the homologies of the wing-veins in this order ; but some of the 
results attained have a much wider bearing, giving a hint as to 
the position of this order in the class Insecta. For this reason, 
after setting forth the conclusions regarding the homologies of 
the trachez of the wings, a brief discussion of the taxonomic 
bearing of some of these conclusions will be given. 
The Homologies of the Principal Trachee of the Wings of Or- 
thoptera. — In this investigation representatives of the Blattide, 
Acrididz, Locustidz, and Gryllide have been examined; no 
living nymphs of members of the Mantidz nor of winged Phas- 
midz were studied. It is not probable, however, that these will 
present serious difficulties. 
The most uniform characteristic of the wings of the four- 
families studied is the structure of the anal area of the hind 
wings. For this reason we will begin our description of the 
tracheation of the wings with this area and proceed cephalad. 
In the Orthoptera the anal area of the hind wings is broadly 
expanded and fanlike in form. The first anal trachea is simple 
(Figs. 74-78 A); the second and third anal trachez coalesce fora 
distance and then separate into several trachez, each of which 
traverses a convex vein of the fanlike portion of the wing. Some- 
times, as in the wing of an Acridid, represented by Fig. 75, the 
common trunk of these two trachez divides into two large 
trunks, which probably correspond to the second and third 
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