WORK UPON VISCERAL AND ALLIED NERVES. 37 



In the cat, Langley found that the similar fibres leave 

 the cord from the fourth to the seventh thoracic nerves — 

 on rare occasions by the third as well — and thus reach the 

 superior cervical ganglion, where nerve cells are interpolated 

 on their course. The grey rami to the first, second and 

 from the ganglion and supply two regions — (i.) a "face 

 third cervical nerves and the cranial rami carry the fibres 

 area," between the eye and the ear, supplied by the latter; 

 and (ii.) a dorsal strip extending from just behind the 

 anterior level of the ears to, as a rule, some point over the 

 fourth vertebrae. 



The next set of nerve fibres have their cells in the 

 ganglion stellatum. These leave the cord in the fifth to 

 eighth thoracic nerves, and from the ganglion are distri- 

 buted by a vertebral ramus to the third to eighth cervical 

 nerves and supply a dorsal strip extending from the fourth 

 cervical vertebra to the front of the third thoracic verte- 

 bra. This strip is narrow above and broadens out below. 

 The ganglion stellatum also sends pilo-motor fibres by its 

 grey rami to the first, second, third and fourth thoracic 

 nerves. These supply areas roughly corresponding to one 

 vertebra each, and thus extend from the third to the seventh 

 or even eighth thoracic vertebra. 



For the remaining ganglia of the chain, the fibres leave 

 the cord from the seventh thoracic to the third or fourth 

 lumbar nerve inclusive. The third is usually the last, and 

 supplies fibres to the parts from the anus to the tip of the 

 tail. As a rule, the nerve cells for these pilo-motor fibres 

 are in the ganglia, from which they are given off to the 

 spinal nerves, though occasionally in the lumbar region, 

 they are placed in the ganglion immediately above. Each 

 grey ramus supplies the skin over about one vertebra. 

 Thus the grey ramus to the fourth lumbar nerve supplies 

 the hairs over the seventh lumbar vertebra and sacrum. 

 There is a curious gap in the distribution to grey rami, for 

 usually that to the sixth lumbar nerve contains no hair 

 fibres. There is, however, no gap in the skin distribution, 

 and the first sacral grey ramus follows the lowest effective 

 lumbar ramus. The first effective ramus below the in- 



