{ REPORT OF THE STATE ENTOMOLOGIST 1907 233 
the first fork of the media, the fork of cubitus, the radio-medial 
cross vein, and the medio-cubital cross vein. Primitively the cord 
was very much zigzagged in and out, and secondarily it often be- 
comes quite straight, but whatever its shifts of position, its ins and 
outs, it is always clearly recognizable, and the parts just cited are its 
essential parts. It is always attached to vein R', but there is the 
most extraordinary diversity in its mode of attachment. It may, 
with the aid of the radial cross vein, be slung from R! upon a truss 
of equal arms (the arms being the base of Rs and portions of 
R**8, see plate 29) ; or, the distal arm may be shortened, as in a host 
of forms (as indicated in the diagram fig. 11) ; or the proximal arm 
may be shortened as in Dolichopeza [ pl. 16, fig. 5] ; or both arms may 
be shortened simultaneously as in Cryptolabis [pl. 30, fig. 1] and 
Peripheroptera [pl. 28, fig. 4] or the radial cross vein may come into 
a position of increased responsibility as in Conosia [pl]. 21, fig. 5] 
or may be brought into direct line with the cord, as in Paratropeza 
[pl. 21, fig. 4]; or, the radial cross vein may atrophy, as in a host 
of forms, leaving the cord supported by the base of the sector alone; 
or, the opposite thing may happen; the tip of R* may turn forward 
and fuse with the tip of R', thus eliminating the radial cross vein, 
with the usual result of leaving a very strong union in its place; and 
the vein R*? may follow it, and the base of the sector may atrophy, 
leaving the cord slung from the radius by R** alone, as in Scambo- 
neura [pl. 16, fig. 6]. But, these shifty parts aside, be it noted that 
the foremost fixed point in the cord is the first fork of the radial 
sector, and the hindmost point is the fork of cubitus, and between 
these two points it had primitively a zigzag, in and out course, 
which has been corrected, shortened and improved chiefly by the 
shortening of these forks, and the divarication of their branches. 
This path of union traverses the cell 1st M*— one might say, is 
interrupted by that cell. Probably the cell 1st M? and probably the 
entire median vein with it, might well have been dispensed with, 
for the more successful of the Diptera have either eliminated it, 
or brought it into quite new relations to adjacent veins. But it 
was present, and its principal fork was interposed squarely between 
the forks of the adjacent veins. That is the burden of inherit- 
ance; for the wing was not made out of dreams, as some might 
have us think —out of hypothetical a prior: fitnesses—out of 
vacancy, to which parts might be added in a rational and beautiful 
manner, but out of a fold of hypodermis, traversed by branching 
tracheae, and secreting chitin about them and between them. The 
