IX. Experiments in examination of the peripheral distribution of the fibres of the posterior roots of some spinal nerves

Abstract

As a step preliminary to some observations on the reflex functions of the spinal cord of the Monkey, I have attempted to make a rather detailed examination of the distribution of the efferent and afferent roots of each spinal nerve, especially in the lower half of the body of that animal. I have recently published some experimental notes on the arrangement of some motor fibres in the lumbo-sacral plexus, and the present paper deals chiefly with the distribution of the afferent fibres of the roots. Previous Observations. In the researches which have had for their subject the peripheral distribution of the posterior roots of the spinal nerves, the plexuses of the Mammalian fore limb have been more studied than have those pertaining to the hind limb. With the exception of the five experiments extant by L. Türck (1856), there seem no experiments on the cutaneous fields of the afferent spinal roots of the Mammalian bind limb previous to my own. This fact may lend interest to observations, especially on so high a type as the Monkey, and I take this opportunity of expressing my thanks to the Royal Society for pecuniary aid, placing that somewhat expensive laboratory animal within my reach.