Abstract: <h3>DISPLACEMENT OF THE MASTOID PROCESS BY THE LATERAL SINUS.1</h3> One of the most common forms of asymmetry in the human skull consists in the right lateral sinus being situated more anteriorly than the left. Trautmann<sup>2</sup>has made extensive investigations into these conditions, and following his ideas I examined a series of 17 picked temporal bones and described them under the title, "Some Practical Remarks on the Anatomy of the Temporal Bone."<sup>3</sup>Basing my conclusions on the measurements of those 17 temporal bones, in which the distance of the most protruding part of the lateral sinus from the suprameatal spine varied from 21 mm. (in a right temporal bone) to 6 mm. (also in a right temporal bone), I concluded that a lateral sinus which comes nearer to the supra-meatal spine than 10.6 mm. can be regarded as displaced forward. The distance in the specimen shown in Figures 1