What vague auroral flittings of human perception pass beneath that horrid crest of the gorilla, as he elevates it in astonishment at encountering a creature of matchless symmetry like the wild ass, of picturesqueness like the zebra, of remote rarity like a beautiful woman! As for cockatoos, parrots, and macaws, I am convinced they are an endless source of amusement to the monkey tribe, who pelt them with nuts to make them scream and scold. Monkeys have a great flow of animal spirits: this, with their imitative talent and quick observation, renders them capable of entertaining ludicrous impressions. But one must be very closely related to the anthropoid ape, if not quite recently derived from it, to tell what they are. There are many well-attested cases of an absolute enjoyment among animals that sometimes rises to the pitch of mirthfulness. One day, Dr. Kane came across a long, icy, inclined shoot, like the artificial coasting-places made by the Russians, down which a long file of white bears went sliding on their hams: at the bottom they jumped up like a crowd of boys, with evident delight, to carry their sleds back to the top of the hill. He says that the signs of pleasure among them were unmistakable. The Canadian fish-otter (_Lutra Canadensis_) loves to do the same thing. He climbs to the top of a snow-ridge in winter, or of a slippery bank in summer, lies on his belly, with the fore feet bent backward, then, pushing with the hind legs, down he goes. So the Russians, with their ice-slides, are only imitating the sport of their own arctic creatures. I suppose that long ago the pleasure derived from an involuntary and accidental slide originated the habit. Lieutenant Dall says that the beavers in Alaska engage in gymnastics for fun. If they find a smooth, miry bank, they betake themselves to sliding down it. And the Californian gray whale loves to play in the shoals where the surf breaks; keeping a wary outlook, so that it continually escapes being beached. Its pleasure is enhanced by the peril. Seals do the same thing when they find a heavy surf. They turn from side to side with half-extended fins, moved apparently by the heavy ground-swell; at times making a playful spring with bended flukes that throws the body clear out of the water, to come down with a heavy splash: then, giving two or three spouts, they settle again under water, to appear perhaps the next moment rolling over in a listless manner with the heavy swell, plainly full of intense enjoyment. If the sea-otter of Siberia escapes into the water from its hunters, it expresses joy and derision by marked gestures, one of which is the putting a paw up over the eyes, as if shading them to regard the hunters. It would seem to be a very slight natural variation when the thumb slips to the point of the nose, and the rest of the paw executes that vibratory sarcastic gesture highly approved by boys.