This paper is a continuation of the line of thought and investigation indicated in my paper entitled "The Glenoid Fossa; the Movements of the Mandible; the Cusps of the Teeth," read before the Southern Dental Association in November, 1895. 1 Up to that time I had not been able to find mention of the facts that, in the movements of mastication, the mandibular condyle moves "not only forward but also downward, causing the ramus to drop, in the anterior and lateral movements of the mandible" and that the condyle on the side toward which the jaw is advancing, in the lateral movements, does not merely "rotate on its axis," otherwise "remaining stationary" as we are taught, but that it also moves both upward and backward, very slightly in many subjects, and not at all in some, but considerably in others. I enlisted the services of men who have access to