On some numerical comparisons of the centripetal and centrifugal medullated nerve‐fibres arising in the spinal ganglia of the mammal

There are in the cat about 0.5 per cent. more fibres in the trunk of a spinal nerve than in the two roots combined, the excess being caused by fibres of small diameter, going probably from the gray ramus to supply the blood vessels or other tissues of the ganglion. The author does not agree with Hardesty in finding fibres arising from cells in the ganglion to end close to it; and concludes from his measurements that fibres of both ventral and dorsal roots taper slightly in size as they pass away from the cord.