( 337 ) 



t lie sympathetic nerve-fibres, intended for the pilo-inotur muscles ot 

 the skin of the trunk in cats, originate in the series of ganglia ot 

 the column of the X. sympathicüs, thai they are conducted along 

 the grey connecting branches towards the relative corresponding 

 spinal nerves, thence following the primary dorsal nerve-trunks and 

 the (dorsal) skin branches of these, to terminate in the pilo-motor 

 muscles of the dorsal portion of the skin. Besides he has demonstrated 

 that by far the greater number of the nerve-fibres, originating in 

 the sympathetic ganglion, the "pilo-motor" nerves as he called them 

 were conducted along the selfsame grey connecting branch towards 

 the one spinal nerve segrnentally corresponding with it, and that 

 along the dorsal skin-branch or branches of this nerve, they jointly 

 reach the skin, where they are distributed within one uninterrupted 

 area, that may be sharply defined. He found further more, thai these 

 skin-areas, supplied with pilo-motor nerve-fibres by the series of 

 sympathetic ganglia form a regular series, arranged on both sides of 

 the mid-dorsal line of the body. As regards the relation between 

 the innervation of the skin by fibres for the pilo-motor muscles 

 from the sympathetic ganglia, and the innervation In sensory liitres 

 from the spinal ganglia, he confined himself to comparing the arran- 

 gement of the pilo-motor skin-areas innervated by the sympathetic 

 ganglia with the results of the researches made by TüRCK and 

 Sherrington about the spinal innervation in the dog and the monkey. 

 Direct comparisons between the sensory and the pilo-motor inner- 

 vation of the skin were not made by him. These have been made 

 recently by me. 



The way in which to do this was clearly indicated. At present, 

 especially after the anatomical studies of Holk on man, we may 

 take it for granted, that there does not occur an interchange of 

 nerve-fibres destined for the skin between the spinal nerves in the 

 trunk-area in mammalia. Consequently the serially arranged skin- 

 branches of the dorsal portion of the body represent separately the 

 different spinal and sympathetic nerve-fibres intended for the dorsal 

 portion of the skin of the trunk from the spinal nerves and sympa- 

 thetic connecting branches in which they originate. In order therefore 

 to obtain a knowledge of the innervation of the dorsal skin-portion 

 relatively by the spinal and by the sympathetic ganglia, it is sufficient 

 to define separately and then to compare the different areas of dis- 



of the R. Society of London, vol. 52, n°. 820, p. 547 — 556 Februari 1893. London. 

 J. N. Langley. The arrangement ol the sympathetic nervous system based chietly 

 upon pilomotor nerves. Journal of Physiology (Foster) vol. 15 n'. 3 p. 170 — 244. 

 1893. Cambridge. 



