When disabled so that it can neither dive nor fly, it is said to face its foe, look him in the face with its clear, piercing eye, and fight resolutely till death.  The gunners say there is something in its wailing, piteous cry, when dying, almost human in its agony.  The loon is, in the strictest sense, an aquatic fowl.  It can barely walk upon the land, and one species at least cannot take flight from the shore.  But in the water its feet are more than feet, and its wings more than wings.  It plunges into this denser air and flies with incredible speed.  Its head and beak form a sharp point to its tapering neck.  Its wings are far in front and its legs equally far in the rear, and its course through the crystal depths is like the speed of an arrow.  In the northern lakes it has been taken forty feet under water upon hooks baited for the great lake trout.  I had never seen one till last fall, when one appeared on the river in front of my house.  I knew instantly it was the loon.  Who could not tell a loon a half mile or more away, though he had never seen one before?  The river was like glass, and every movement of the bird as it sported about broke the surface into ripples, that revealed it far and wide.  Presently a boat shot out from shore, and went ripping up the surface toward the loon.  The creature at once seemed to divine the intentions of the boatman, and sidled off obliquely, keeping a sharp lookout as if to make sure it was pursued.  A steamer came down and passed between them, and when the way was again clear, the loon was still swimming on the surface.  Presently it disappeared under the water, and the boatman pulled sharp and hard.  In a few moments the bird reappeared some rods farther on, as if to make an observation.  Seeing it was being pursued, and no mistake, it dived quickly, and, when it came up again, had gone many times as far as the boat had in the same space of time.  Then it dived again, and distanced its pursuer so easily that he gave over the chase and rested upon his oars.  But the bird made a final plunge, and, when it emerged upon the surface again, it was over a mile away.  Its course must have been, and doubtless was, an actual flight under water, and half as fast as the crow flies in the air.

The loon would have delighted the old poets.  Its wild, demoniac laughter awakens the echoes on the solitary lakes, and its ferity and hardiness are kindred to those robust spirits.

XII

One notable difference between man and the four-footed animals which has often occurred to me is in the eye, and the greater perfection, or rather supremacy, of the sense of sight in the human species.  All the animals—­the dog, the fox, the wolf, the deer, the cow, the horse—­depend mainly upon the senses of hearing and smell.  Almost their entire powers of discrimination are confined to these two senses.  The dog picks his master out of the crowd by smell, and the cow her calf out