MIGRATIONS WITHIN THE PERMANENT REGION. 153 



1874 tbe course was from the west and northwest. This would indicate 

 that they flew from the great pUiiiis lying mainly between the north 

 and south branches of the Saskatchewan Kiver, beyond longitude 105° 

 (approximate). In 1875 the young which hatched from eggs laid the 

 previous autumn flew in a general southeast course, the same as that 

 pursued by their parents, and this direction of their flight took them in 

 large numbers into the region about the Lake of the Woods, where 

 they could do little harm, while small, unimportant swarms entered 

 Minnesota. In 1875, 187G, and 1877 no swarms arrived in Manitoba 

 from the regions lying westward or northwestward. 



From the foregoing facts, we may conclude that the whole tier of 

 States from Texas to Minnesota, as well as the Manitoba settlements, 

 are in locust years always invaded by foreign swarms of locusts, start- 

 ing mainly from the region which we have described as the permanent 

 breeding-grounds. The return flights which we are now to consider, 

 are the young hatched from eggs laid the previous summer and autumu 

 by the foreign swarms. 



MIGRATIONS OF THE LOCUST WITHIN THE PERMANENT BREEDING- 

 GROUNDS. 



Montana. — In Montana and that region of British America lying north 

 of this Territory, the course of the migrations have been ascertained 

 with a good degree of certainty, and we begin with the northernmost 

 portion of the permanent breeding area, because it is in Montana that 

 most of the swarms that fly into Eastern Idaho and Utah, as well as, 

 perhaps, Wyoming, and sometimes even Colorado, usually originate. 

 We will arrange our data by years and localities, and then draw gen- 

 eral conclusions from the observations made since the settlement of 

 Montana. 



In 1862, between Sun Eiver and Fort Benton, swarms were seen in 

 August flying in a southerly direction toward Sun Eiver from the direc- 

 tion of Fort Benton. 



In 18G3 they were seen at Fort Benton flying from the east, and at 

 this point the locusts always come from the northeast and east, and de- 

 part in a west or southwest course. In 1873, locusts laid their eggs at 

 Fort Benton and flew west and south. 



In 1873, 1874, 1875, and 1877, locusts visited Fort Benton, flying from 

 the northeast, more generally east and southeast, and departing generally 

 in a southwest course. In 1876 the course was from the northwest, 

 immense swarms nearly depopulating the country about Fort Benton 

 and the whole region northward to near Fort Edmonton, a distance of 

 about 200 miles, and flew east. At Forts Belknap and Browning all 

 were observed to fly east at the end of June and early in July, flying 

 eastward as soon as they were fledged. These were undoubtedly the 

 swarms that invaded Minnesota, Iowa, and Nebraska late in the sum- 

 mer of 1876. That this exodus of locusts extended into the basin of the 



