In its early stage this disease is so subtle and slow that it is months in developing; and this feature renders it all the more deadly, through the spread of infection long before the ailment can be discovered. One of our antelope arrivals, apparently in perfect health when received, was on general principles kept isolated in rigid quarantine for two months. At the expiration of that period, no disease of any kind having become manifest, the animal was placed on exhibition, with two others that had been in the Park for more than a year, in perfect health. In one more week the late arrival developed a swelling on its jaw, drooled at the corner of the mouth, and became feverish,--sure symptoms of the dread disease. At once it was removed and isolated, but in about 10 days it died. The other two antelopes were promptly attacked, and eventually died. The course of the disease is very intense, and thus far it has proven incurable in our wild animals. We have lost about 10 antelopes from it, and one deer, usually, in each case, within ten days or two weeks from the discovery of the first outward sign,--the well known swelling on the jaw. One case that was detected immediately upon arrival was very persistently treated by Dr. Blair, and the animal actually survived for four months, but finally it succumbed. From first to last not a single case was cured. In 1912, the future of the prong-horned antelope in real captivity seems hopeless. We have decided not to bring any more specimens to our institution, partly because all available candidates seem reasonably certain to be affected with lumpy-jaw, and partly because we are unwilling to run further risks of having other hoofed animals inoculated by them. Today we are anxiously wondering whether the jaw disease of the prong-horn is destined to exterminate the species. Such a catastrophe is much to be feared. This is probably one of the reasons why the antelope is steadily disappearing, despite protection.