78 THE CHINCH BUG. 
RELATION OF THE INLAND AND BEACOAST SHORT-WINGED FORMS. 
It is possible thai the short-winged form of chinch bug found in 
Ohio is precisely the same form as that found along the seacoasts, 
hut it seems to the writer that the inland form originating from this 
maritime short-winged element, instead of acquiring wings of normal 
length as it drifted away from the coast, has really moved in the 
other direction, and the wings have become still further aborted. 
It will be observed by the illustrations given of both the inland and 
maritime short-winged forms (see figs. 3 and 4) that in some of the 
former the wings have become so aborted as to become almost invisi- 
ble, while in the latter, though the wings are very much shortened, 
they are nevertheless very clearly to be observed. It would seem. 
then, that we might reasonably presume that the species was orig- 
inally Long-winged, but, living along the seashore, the winged indi- 
viduals have either flown each year inland or else been blown into the 
sea to such an extent that a short-winged form has thus been evolved 
which was unable to migrate and not easily blown into the sea. In 
pushing inland while the country was still inhabited by the aborig- 
inees another source of destruction would confront these insects in 
the annual recurrence of fires whereby vast areas of country were 
burned over in autumn, winter, or early spring, and these must have 
destroyed very many of the hibernating insects, while such indi- 
viduals as migrated to sections not so burned over would escape 
destruction. 
PROBABLE COURSE OF DIFFUSION. 
Let us suppose that the species originally worked it> way north- 
ward from South America, or even Panama, along the lowlands be- 
tween the more mountainous interior and the Gulf of Mexico until 
it reached Texas with its vast areas of level country extending not 
only aero— the State itself, but northward into British America, and. 
generally -peaking, with the exception of the Ozark Mountains in 
Missouri and Arkansas, eastward to the Appalachian system extend- 
ing from Cape Gaspe, Quebec, Canada, to northern Alabama. This 
area is more or le>s covered with a grass flora that affords ample food 
for these insects, and it would seem that then 1 was here offered every 
incentive t<» migration broadly to the northward and eastward, and 
at the same time there would be the Gulf coast along which those 
individuals which either could not or did not migrate inland could 
make their way as had their progenitors along the coast in Mexico. 
( See fig. 1 7. ) 
Now. it would appear a- though the short-winged individual-, if 
there were any such, would remain along the coast, while the long- 
winged individuals would, at leasl more or less of them, migrate in- 
land, and at leasl some of these, but far more of those unable to flv. 
