Electro-physiology and electro-therapeutics : showing the best methods for the medical uses of electricity / By Alfred C. Garratt.

implanted into the gray substance of the cord, while others apparently beoome continuous with the longitudinal fibres of the cord, gives an argument in favor of the views of Dr. M. Hall. Moreover, it is distinctly understood that many anatomists still hold to the belief that some of the fibrils in each nerve root are continuous with the longitudinal fibrils of the cord; yet this by no means is evidence that they actually pass along the cord for any great portion of its length, far less that they pass upwards continuously to the gray matter of the cerebrum. Besides, there is a general agreement that the great bulk of the fibres which constitute the roots of the nerves of any segment of the spinal centre, are implanted in the gray matter of that segment, and do not pass beyond it. It is now shown, also, that the white matter of the cord does not increase in amount from be- low upwards, as it ought to do according to Dr. M. Hall's views, but is, in truth, greatest where there is the most ganglionic enlargement. These facts seem to justify, he goes on to say, after referring to the views of Todd and Bowman, that the spinal cord is the chief centre for the roots of the spinal nerves; that a consider- able portion of the white strands of the cord is composed of fibres which are passing only a little way up or down the spinal cord, so as to reach segments of its own ganglionic centre, a few removes from the point at which the nerves join the cord ; and that but very few, if any, strands or fibrils pass continuously between the roots of the nerves and the encephalic centres. We are not disposed, however, to deny utterly the passage of some few such continuous fibres; indeed, it seems highly probable, although not actually demonstrated, that some few do so extend. We notice another difficulty, arising from the doctrine of the " distinct and continuous nerve-fibre system," which has refer- ence to the emotional actions. These actions were supposed by Marshall Hall to take place through the instrumentality of the true spinal fibres; but this doctrine was objected to, by Dr. Car- penter, on the grounds that emotional actions may, and do, take place in parts which are paralyzed as to the will. Dr. Carpenter considered, therefore, that the emotions can only be excited 41* *