obtained the spinal canal can be opened in this way more quickly than by any other method. In private practice the noise made by the hammer upon the head of the handles of the chisels is unpleasant, and should be avoided by the use of felt or something else on the head of the chisel or mallet to deaden the sound. Another easy and convenient way of opening the spinal canal posteriorly is the cutting of the laminæ by means of special bone-forceps designed for this purpose. The cutting-edges may engage the laminæ from without or the lower blade may be introduced into the canal as a blunt probe, while the upper blade cuts down upon it through the side of the arch. Such bone-forceps should be very strong and have long handles to give sufficient purchase, as a good deal of force is necessary to cut through the laminæ. With a good instrument the canal can be opened in this way in about 10-15 minutes. It requires much less skill than is needed for good and quick work with the Brunetti chisels, and for that reason is recommended, as is also the use of Luer’s rhachiotome, for the general practitioner. In the case of marked curvatures of the spine it may be impossible to use either rhachiotome or Brunetti chisels. The straight single chisel and small saw can be used on the concave and convex sides of the curvature respectively. In children and young adults the canal can be easily opened with the bone-forceps. After the removal of the posterior wall of the spinal canal the peridural adipose tissue and the dural sac are exposed in the canal. The cord may now be removed with dural sac intact, and when the cord is soft this should be done, but in so doing the spinal fluid is likely to be lost; and, as it is very important to obtain a knowledge of the amount and character of this fluid, care should be taken to preserve it. With the block placed under the cervical region to keep the cervical and dorsal vertebræ higher than the lumbar the dural sac may be opened in the median line from above downward. The cervical dura is grasped with a pair of forceps and lifted so that a cut can be made in it with the small bent, probe-pointed shears. The blunt probe-point is then introduced into the subdural space and the dura cut in the median line downward toward the sacrum. With care the arachnoideal sac with its fluid may be preserved intact. What fluid there is in the subdural space will collect in the lumbar region and may be secured while the lumbar dura is cut. The fluid in the subarachnoideal space will likewise collect in the lower portion of the cord, and it is best at this stage of the operation to introduce a sterile pipette through the delicate arachnoid and draw up the fluid, preserving it for bacteriologic and microscopic examination.