I could see the scouts galloping along the flank of the herd nearest us, trying to find an opening among them into which they might penetrate; while every now and then they let fly one of their arrows into the neck of an animal.  As to turning the herd, or preventing it from crossing the stream, they might as well have attempted to stop the falls of Niagara in their downward course.  With a tramp which shook the earth, and terrific bellowings sounding far across the plain, onward rushed the seemingly maddened creatures, tossing their heads, throwing high their tails, and turning up the earth in their course.