The topography of root fibres within the sciatic nerve trunk of the dog.

The architecture of the fibres in the sciatic nerve of the dog has been analysed by following the degeneration of fibres resulting from division of the individual spinal nerves which contribute to the sciatic nerve. A pattern has been demonstrated which varies in part with the size of the contribution to the sciatic nerve from each of the spinal nerves L6, L7 and S1. The redistribution of the fibres of each spinal nerve to form the various branches of the sciatic nerve is also described, and the significance of these arrangements is discussed.