Until 1899 there was little or no knowledge in regard to the physiologic and pathologic changes in the alveolar process during tooth regulation. The question had frequently been asked, What changes take place when pressure is brought to bear on the teeth. At that time I commenced a series of experiments on dogs, the results of which were published in the fourth edition of my work on "Irregularities of the Teeth and Their Treatment." Impressions of the dogs' mouths were taken in modeling compound, and caps of German silver were made for the cuspids. A jack-screw was soldered to the caps. The dogs were securely fastened into a V-shaped box with cotton bandages, chloroformed and the appliances cemented into place. Muzzles were then placed on the dogs' heads and their forefeet tied to prevent removal of the appliance. The muzzles and bandages were removed twice a day for the purpose