io6 Neurological Technique 



clip the nerve on the peripheral side of the spinal ganglion. In 

 this way the spinal ganglion and the fusion of the dorsal and 

 ventral nerve-roots to form the nerve-trunk will be obtained 

 intact. The finer divisions of the roots and their attachment to 

 the spinal cord, being inclosed by the dura mater, will be 

 protected. Removal from the vertebral canal will now be an 

 easy matter. Begin at the sacral end. Gently lift the organ by 

 applying the forceps to the dura, being careful not to press or 

 crush the spinal cord, and with a small scalpel, frequently using 

 the handle, free the organ from its adherence to the ventral 

 side of the vertebral canal. Then, with sharp scissors, separate 

 the spinal cord from the medulla at the level of the first cervical 

 nerve, and place the whole into the fixing fluid. If it has been 

 removed with dura mater intact, it will be better to make small 

 openings in the dura at intervals to facilitate the penetration of 

 the fluid. 



In order that the spinal cord may become fixed in its normal 

 extended shape, it should either be laid straight in a vessel long 

 enough to accommodate it, or, better, a tall glass cylinder may 

 be used. In the latter case it will be best to use a strip of glass 

 narrow enough to fit into the cylinder. Extend the specimen 

 on the strip of glass and tie it at each end. Let the dura only 

 be involved in the tying. It may be necessary to use a needle 

 and thread. 



During the process of removal the specimen should be kept 

 moist either with physiological salt solution (VII, A, p. 43) or 

 with water. 



To remove the brain with the dura mater intact is more diffi- 

 cult than it is with the spinal cord. It is not so difficult to 

 remove the brain with that part of dura in position which covers 

 its dorsal and lateral aspects. This, together with the falx 

 cerebri and the tentorium ^nA falx cerebelli, will give little trouble. 

 But that part of the dura inclosing the ventral surface of the 

 brain, because of the various grooves, fossae, and foramena, is so 

 firmly attached to the base of the cranium that the attempt to 

 remove it will endanger the brain and especially the cranial 



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