Dr. F. Jacobs, of Newark, O., explained his method of making sections of teeth for the microscope. After cutting from both sides to the centre upon a coarse wheel, the thin section is placed upon a cork and held against a fine wheel kept wet all the while. It is stained with carmine ink or sassafras oil and mounted in balsam. Dr. Fletcher, Cincinnati, O., Paper, "Dental Implantation." We have been relying upon the wrong tissue for success. The pericementum was formerly supposed to be necessary for success. Dr. G. L. Curtiss was first to remove this portion before implanting. Very few cases are permanent successes. Reports of failure are now coming in quite frequently. Dr. Fletcher used for experiments a goat and the teeth of a small dog. Owing to difficulties in holding the teeth in position, they were maintained in place by sewing over the integument. The teeth were inserted in the bone rather than the alveolus. Parts of the crowns were removed so as not to prove so great an irritant to the integumentary covering. Bichlorid was used throughout. After nine months they were opened into. In all cases periosteum had grown over them. All but two had almost entirely disappeared. In one case, cementum became reorganized and grew at the expense of the dentine. The pericementum cuts no figure in implantation of teeth. Implanted teeth can never be successful for these reasons: First, teeth are developed from a different structure than bone. If dried pericementum took on new life and performed its functions as before, it would be a success. If we could implant immediately after a tooth is extracted, success is more probable. It would be equal to skin or bone graft. If the cementum becomes reorganized, it can grow only at the expense of the dentine. If resorbtion takes place in vital tissues it certainly is so in dead tissues. So it would be but a few years until the whole root would be replaced by a new material, probably bone, since it is produced by bone-producing tissue. The experiments of Drs. Hopkins and Penrose were reviewed in this connection and the following deductions drawn. First, sterilized bone in favorable conditions undergoes organization. When acted upon by periosteum is absorbed, and when in a narrow cavity, and not too large in bulk, organization and absorbtion both take place. Second, these processes go on most actively between five and eight weeks. According to Dr. Wm. Savory, tight ivory pegs were more quickly absorbed than loose ones. He draws the following conclusions: First—the operation of implantation has fallen into disrepute, either from failure or loss of confidence. Second—when the root is covered with dried periosteum the membrane is absorbed before union takes place, and when union does occur it is probably that of ankylosis between vascular cementum and the surrounding bone. In view of which, teeth with much thickness of cementum are to be preferred, and should be denuded of the membrane before the operation.