262 BULLETIN NO. VII. 
rather larger and darker colored than the bison of the plain. 
The mountain variety is not probably essentially different, 
The bison is a perpetual nomad; indeed, the gregariousness 
of the animal makes this a necessary corollary. The migra- 
tions of the herd are caused by seasonal changes which drive 
them northward, or toward the mountains at one time and in 
the opposite direction at another, but the details of their wan- 
derings are controlled by chance variations in food and water. 
The vast herd, often thousands strong, consumes and destroys 
large areas of herbage in an incredibly short time and the 
mammoth pastures of our continent were none too large for the 
buffalo in their best estate. The prairie fires and inroads of 
locusts were frequent causes of change of base, while the posi- 
tion of streams and springs acted as determinants upon the 
course of the moving column. Before the encroachment of 
settlements and other interference the major migrations were 
so constant and uniform that the approximate date of the ar- 
rival and departure of the herd could be predicted quite closely. 
Like most animals accustomed to travel in large companies the 
buffalo loses to a large degree its sense of individual respon- 
‘ sibility, and acts but as a member of the community, rushing 
blindly on in case of danger, impelled by a common instinct, 
and frequently plunging headlong into dangers which an indi- 
vidual alone would avoid. They are said to evince great dex- 
terity in climbing and descending steep banks and make good 
headway over steep ground, although generally choosing the 
most direct and level routes. When upon their migrations 
herds frequently cross large rivers, buffeting a rapid, ice-filled 
current with undaunted courage. At times great losses are 
suffered in the crossing of such streams, especially when great 
herds crowd upon the ice. Stupidity and *‘bull-headedness,” 
which are marked characteristics of all bovines, seem to be un- 
usually developed in the bison, and in the exhibition of these 
traits it gives evidence of what in another animal might be 
regarded as courage. In reality, however, the buffalo is timid 
and distrustful. Avery remarkable trait is repeatedly referred 
to by those familiar with its habits. The animal is not stopped 
by any danger in front but is frequently thrown into great con- 
fusion by unwonted objects in the rear, as the incident given 
by Colonel Dodge, in the Chicago Inter-Ocean, 1875, will illus- 
trate. 
‘The winter of 1871-72 was unusually severe in Kansas. 
The ponds and smaller streams to the north were all frozen 
