We should be able to find for man an energy formula distinct from that for wild and domestic animals and, further, an energy formula for civilized man. This became our quest, While Mrs. Crile and I were hunting in Africa in 1927, two phenomena well known to hunters of big game excited our attention. The first was that an antelope, a lion, or any high powered animal, when shot through the heart in such a way that the circulation of the blood is immediately arrested, may continue to run at top speed for a distance of a hundred or more yards before he falls dead. This fact challenged credulity, for, from my observations in war, I had found that death results instantly from a comparable shot through the heart in man. The second phenomenon was the explosive outburst of speed seen in the long leaps of the impala in escape and the incredibly high and long bound of the lion in attack. In contrast, we observed that if an animal is shot through the brain or high in the brachial plexus near the spinal column, it will never move again if shot through the heart, it may run a hundred yards or more and even complete its attack if shot so that the energy of the bullet suspends momentarily the action of the brain or creases the animal, the animal may fall, then jump up, and bound away or complete its charge.