20 REPORT UNITED STATES ENTOMOLOGICAL COMMISSION. 
in comparison with the whole, area which tonus the native home of the 
species, but fortunately in one respect this cultivated belt occupies in 
part, at least, the point of departure of the swarms which invade the 
temporary region. This fact, therefore, renders it more important that 
it be occupied by an agricultural population. 
Although we have admitted that we are unable to present any plan 
of exterminating the locusts that holds out sufficient promise of success 
to justify the general government in undertaking it, it does not neces- 
sarily follow that there is no plan of modifying the evil which the gov- 
ernment would be justified in undertaking. On the contrary, if the 
views we have advanced be correct, they suggest a means by which the 
general government might greatly aid in bringing about the desired re- 
sult; and fortunately the result would be beneficial even should we be 
mistaken in the opinions advanced. 
As will be seen by what has been stated, the great desideratum is to 
settle the cultivable belt alluded to as rapidly as possible with an agri- 
cultural population. Wherever valuable aud permanent mines are dis- 
covered in the neighboring mountains, the arable areas in the vicinity 
will be taken up and cultivated to an extent at least sufficient to sup- 
ply the demand for agricultural products, as in parts of Colorado. But 
there are large sections where no such influence will be brought to bear r 
and this is the case along that portion of the belt where the agricultural 
population is most needed for the purpose mentioned. 
An examination of map No. 1, in our first report, will show that a 
comparatively Umited belt in Central Montana, extending from the Big 
Horn Mountains northwest to the British line, a little west of Cypress 
Hill, forms the turning-point of the locust movements. Without now 
repeating the data which may be found in that report, we may summa- 
rize it by saying that from this region a large portion of the swarms come 
which visit Dakota, Minnesota, Nebraska, and Kansas; from this area 
also proceed a large portion of the swarms that move southwest into 
Idaho and Utah ; this appears to be the point to which most of the re- 
turning swarms from the temporary region direct their flight. 
That there are other areas in the permanent region which appear to 
be special breeding-grounds, as points of departure, is certainly true, but 
none to such an extent as this, and none affecting an agricultural area 
bearing any comparison with the area affected by the locust swarms origi- 
nating in this belt. 
Even should it be shown by subsequent investigations that as a rule 
the swarms falling on the temporary regions come from intermediate 
points, as Central and Southern Dakota and Northwestern Nebraska, 
the facts already ascertained warrant us in asserting that, as a very gen- 
eral rule, they originate in the belt mentioned. 
It is evident, therefore, that if any method can be devised by which 
an agricultural (not pastoral) population can be thrown into this belt it 
will form one of the best possible means of modifying the evil. If they 
