DISTANCE TO WHICH A SWARM MAY MIGRATE. 
83 
contending that those observed in England in 1784 must have originated 
there. Koppen appears to lean toward the same opinion, at least so far 
as Southern Eussia is concerned. But, as heretofore intimated, the facts 
given by Keferstein and Koppen themselves show beyond doubt that 
the locusts do pass beyond the limits of their usual hatching grounds 
into sections where they are not able to maintain their existence. 
While the Tartary of the older entomologists and travelers is an un- 
certain laud, and while we must admit that the belief held by many that 
the locusts in a single season or single migration pass from the regions 
of the Caspian Sea to Germany is not based upon any ascertained fact, 
and unfounded, yet that by successive stages they have passed from 
Bessarabia and Southern Bussia into Poland and Germany has been 
established beyond doubt. That in our own country G. spretus has mi- 
grated in a single season from Montana into Nebraska and Kansas ap- 
pears now to be too well established to any longer admit of doubt. The 
writer for some time was disposed to doubt this as was also Mr. S. H. 
Scudder, but the facts ascertained by the commission have proven it 
beyond question. 
The most positive evidence we have in reference to the distance 
swarms of the Bocky Mountain locust travel is to be drawn from the 
records of return nights. 
As we have now ascertained somewhat definitely the date at which 
they acquire wings at different latitudes we can judge with considerable 
certainty as to the latitude in which an early swarm seen flying north- 
ward originated. As our record of flights in 1877 is very full and we 
may say almost complete as to the area east of the mountains, we are 
enabled to trace with almost positive certainty the earlier swarms to 
their starting point. Those hatched in Kansas did not commence to 
move until in Juue, the earliest noted being about the 10th or 12th, but 
it is quite probable some small swarms left the more southern parts a 
few days earlier. In the southern part of Nebraska there was no gen- 
eral movement, but the earliest of which we have any record was in the 
latter part of June. In Texas, the movement commenced soon after the 
middle of April, from the central part of the State, and by the 10th of 
May all had departed. 
On the 15th of May a swarm was observed at Amazon, in Franklin 
County, Nebraska, flying north ; swarms were observed two days later, 
passing northward over Trego County, Kansas. From this time until 
the 2ath of the month, numerous swarms were observed passing north- 
ward over the western part of Kansas and Nebraska, and the northeast 
corner of Colorado. And in the latter part of the month some swarms 
from the south settled down at the Black Hills, and there deposited their 
eggs. As the locusts in Kansas, Nebraska, Colorado, and in this lati- 
tude were not yet fully fledged, it is certain that those seen flying came 
from some point south of Kansas ; and from the meager reports we re- 
ceived from Indian Territory (the only section from which they are not 
