THE WINGS OF INSECTS. 
J. H. COMSTOCK anp J. G. NEEDHAM. 
CHAPTER II. 
The Venation of a Typical Insect Wing. 
THERE are certain features of the venation of the wings of 
insects which occur in the more generalized forms of so large a 
proportion of the orders of this class that we are warranted in 
regarding them as typical of winged insects as a whole, and we 
are able to present a hypothetical type to which the wings of 
all orders may be referred. 
This of course implies, what we believe to be the case, that 
all of the orders of winged insects have descended from a com- 
mon winged ancestor. For it is not probable that had wings 
arisen more than once in this class that they should agree 
closely in their structural characteristics. 
The recognition of the features of the wing venation that are 
common to the various orders of insects has been a matter of 
slow growth. Most writers on the subject have only attempted 
to work out the homologies of the principal veins within the 
limits of a single order; and thus have arisen the various 
systems of nomenclature of the wing-veins, which have done 
much to delay an appreciation of the uniformity of structure 
which really exists. 
We will not take the space to trace out in detail the develop- 
ment of the idea that a uniform nomenclature of the wing-veins, 
based on homologies and, therefore, applicable to all orders, is 
possible. In 1870 Hagen attacked the problem in a paper, 
entitled “Ueber rationelle Benennung des Geäders in den 
Flügeln der Insekten.”! But this essay apparently had little 
influence beyond calling attention to the importance of the 
subject. It was not till the appearance of the classic contribu- 
1 Stettiner Entomologische Zeitung, Bd. xxxi, pp. 316-320. 
