In our Zoological Park, day by day and hour by hour our people carry into practical effect their knowledge of the psychology of our mammals, birds and reptiles. In view of the work that we have done during the past twenty-one years of the Park's history, we do not need to apologize for claiming to know certain definite things about wild animal minds. It is my belief that nowhere in the world is there in one place so large an aggregation of dangerous beasts, birds and reptiles as ours. And yet accidents to our keepers from them have been exceedingly few, and all have been slight save four. Twenty-five years ago I endeavored to plan for the Zoological Society the most humane and satisfactory bear dens on earth. Fortunately we knew something about bears, both wild and captive. Never before have we written out the exact motif of those dens, but it is easily told. We endeavored to give each bear the following things: A very large and luxurious den, open to the sky, and practically on a level with the world; Perfect sanitation; A great level playground of smooth concrete; High, sloping rocks to climb upon when tired of the level floor; A swimming pool, always full and always clean; Openwork steel partitions between cages, to promote sociability and cheerfulness; Plenty of sunlight, but an adequate amount of shade; Dry and dark sleeping dens with wooden floors, and _Close-up views of all bears for all visitors._ If there are anywhere in the wilds any bears as healthy, happy and as secure in their life tenure as ours, I do not know of them. The wild bear lives in hourly fear of being shot, and of going to bed hungry. The service of our bear dens is based upon our knowledge of bear psychology. We knew in the beginning that about 97 per cent of our bears would come to us as cubs, or at least when quite young, and we decided to take full advantage of that fact. All our bears save half a dozen all told, have been trained to permit the keepers of the dens to go into their cages, and to _make no fuss about it._ The bears know that when the keepers enter to do the morning housework, or at any other time for any other purpose, they must at once climb up to the gallery, above the sleeping dens, and stay there until the keepers retire. A bear who is slow about going up is sternly ordered to "Go on!" and if he shows any inclination to disobey, a heavy hickory pick-handle is thrown at him with no uncertain hand.