1923] 
The Wing-Venation of Insects 
123 
ON THE WING-VENATION OF INSECTS 
By Aug. Lameere. 
Translated by Austin M. Brues 
The admirable method discovered by Comstock and Need- 
ham/ of showing homologies in the wing neuration of various types 
of insects does not allow us, unfortunately, to discover veins 
which have disappeared during the course of evolution. It is 
absolutely necessary to make a study of fossil forms in order to 
complete the ontogenetic data by means of information derived 
from the connections and topography of the veins in ancestral 
types which no longer exist. 
No living insect possesses neuration as complete as that of 
many fossils from the coal measures; the result is that Comstock’s^ 
scheme of the fundamental primitive neuration is inexact, for 
it is based on living Perlids. To take this scheme as a basis of 
comparison leads to confusing entirely different veins under the 
same heading. That is what has happened notably with the Ep- 
hemerids and Odonata, of which the neuration does not seem to 
me to have been well understood. 
We know that ontogentic study shows two tracheae pene- 
trating the wing; the ramifications of the anterior trachea cor- 
respond to the costal, sub-costal, radial, and median nervures; 
those of the posterior trachea correspond to the cubital and the 
three anal nervures. 
The radial nervure presents two branches: the radial, strictly 
speaking, and its sector. 
In the wings of the Ephemerids, the Odonata, and the Proto- 
hemiptera from the coal measures, the median nervure forks, not 
far from the base of the wing, into two branches which I have 
termed the anterior median and the posterior median^; that is 
to say the median has exactly the same configuration as the radial, 
so that the posterior median can be considered as the sector 
of the anertior median. The comparison of the form of the median 
iSurla nervation alaire des Insectes. Bull. Clasp, des Sci. Acad. Roy. Belgique, 1922 pp. 
38 - 149 . 
