It seems to me that the gray squirrel barks and the red squirrel chatters, scolds, and at times swears, chiefly for the fun of hearing himself make a noise. In the red squirrel it is impudent and defiant; and usually you hear it near your camp, or in your own grounds, where the rascals know that they will not be shot. The playful spirit seems to be inherent in the young of all the Felidae. The playfulness of lion, tiger, leopard and puma cubs is irresistibly pleasing; and it is worth while to rear domestic kittens in order to watch their playful antics. I have been assured by men who seemed to know, that wolf and fox cubs silently play in front of their home dens, when well screened from view, just as domestic dog puppies do; and what on earth can beat the playfulness of puppies of the right kind, whose parents have given them red blood instead of fat as their inheritance. Interesting books might be written about the play of dogs alone. The play of the otter, in sliding down a long and steep toboggan slide of wet and slippery earth to a water plunge at the bottom, is well known to trappers, hunters, and a few naturalists. It is quite celebrated, and is on record in many places. I have seen otter slides, but never had the good luck to see one in use. The otters indulge in this very genuine sport with just as much interest and zest as boys develop in coasting over ice and snow with their sleds. Here at the Zoological Park, young animals of a number of species amuse themselves in the few ways that are open to them. It is a common thing for fawns and calves of various kinds to butt their mothers, just for fun. A more common form of infantile ruminant sport is racing and jumping. Now and then we see a red buffalo calf three or four months old suddenly begin a spell of running for amusement, in the pure exuberance of health and good living. A calf will choose a long open course, usually up and down a gentle slope, and for two hundred feet or more race madly to and fro for a dozen laps, with tail stiffly and very absurdly held aloft. Of course men and beasts all pause to look at such performances, and at the finish the panting and perspiring calf halts and gazes about with a conscious air of pride. All this is deliberate "showing off," just such as small boys frequently engage in. Elk fawns, and more rarely deer fawns, also occasionally indulge in similar performances. Often an adult female deer develops the same trait. One of our female Eld's deer annually engages in a series of spring runs. We have seen her race the full length of her corral, up and down, over a two hundred foot course, at really break-neck speed, and keep it up until her tongue hung out.