18 BULLETIN NO. 2, DIVISION OF ENTOMOLOGY. 
to the possible or probable causes for the sudden and general disap- 
pearance of this insect at this time from this vast area of country that 
in every respect is so admirably adapted to its increase in the greatest 
numbers possible; for we already know how general had become its 
distribution during the years 1875 and 1876, and how, in the spring of 
1877, everywhere, soon after the young had been hatched, they began 
to dwindle from various causes already known to us, until but a very 
small per cent. of what had hatched remained; how these from weak- 
ness were unable to migrate in every instance,and where they suc- 
ceeded and deposited their eggs, how accident after accident befell 
’ them, until they were almost entirely obliterated from the face of the 
earth. Ineed not enter upon a discussion of these facts that are already 
known and that have been pretty widely circulated by the Entomolog- 
ical Commission, of which ny worthy chief was head. Aside from this, 
however, I consider it my duty to give all the information possible in 
reference to its probable appearance and movements in the future, in 
order that the farmers and horticulturists of our country in general 
may know how to plant accordingly. 
For a distance of some forty or more miles below McLeod the country 
along the river retains the characters it has in the vicinity of the above- 
named place, after which it gradually changes to a high, dry, and al- 
most level plain, the surface of which is covered by a medium growth 
of short grasses somewhat superior to those of the plains of western 
Dakota, but far inferior to those of the prairies of Nebraska, Iowa, 
Kansas, Minnesota, and eastern Dakota. 
The river bottoms become less wide, the hills higher, and timber less 
abundant. At long intervals deep coulees extend back from the river 
‘into the plains and form almost impassable barriers to wagon or cart 
travel. These coulees in the spring-time are the beds of small streams 
that are formed by melting snows. Some of them support a meager 
growth .of choke cherry and Buffalo berry bushes on their sheltered 
sides, but otherwise there is but little trace of vegetation which bears 
the semblance of shrub or tree away from the river banks. 
After passing the mouth of the Old Man’s or Arrow River and enter- 
ing the Belly River, there begin to be traces of coal in the high and 
almost vertical cliffs that are now quite frequent on both sides of the 
river. These cliffs, for the most part, are composed of clayey soil 
highly impregnated with the various salts of soda and potash, and oc- 
casionally a magnesia spring is passed. But very little if any vegeta- 
tion grows on these steeply-worn hills, and they look quite desolate. By 
the time the St. Mary’s River is passed, these cliffs contain some rocks 
of a more substantial character; the coal signs have developed into coal 
seams, and now and then a stratum or perhaps a series of strata is 
passed that contain numerous fossils of various kinds. All these char- 
acters just noticed continue to become more and more decided from 
time to time until they finally culminate in a narrow gorge, like a valley, 
