40 SCIENCE PROGRESS. 



fibres issuing by the third to eleventh thoracic inclusive, 

 but chiefly by the fifth to ninth inclusive. For the hind 

 limb, from the eleventh thoracic to third lumbar in- 

 clusive, mainly however in the twelfth thoracic to second 

 lumbar inclusive. 



Langley ^ finds that the fibres for the upper limb termi- 

 nate in the cells of the ganglion-stellatum ; those for the 

 hind limb in cells in the sixth and seventh lumbar and first 

 sacral ganglia. The fibres issuing from these cells run 

 chiefly into the corresponding grey ramus, but in a few 

 cases may run down the sympathetic chain and issue by the 

 grey ramus of the next ganglion. Langley," in a later paper 

 on the constrictor supply to feet of the cat, shows that they 

 leave the cord in the fourth to ninth thoracic nerves 

 inclusive for the fore foot ; and to the hind foot in the 

 twelfth thoracic to third lumbar nerves with an anterior 

 plexus, or in the twelfth thoracic to fourth lumbar with a 

 posterior plexus. On the whole, the two results agree 

 when we remember that Bayliss and Bradford's experi- 

 ments were performed upon the dog, and involved the 

 larger part of the limb, and that Langley's observations 

 were made on the cat, and were restricted to the vessels of 

 the feet. 



E. Cyon,^ in 1868, by studying the effects upon the 

 temperature of the limb after section of the sympathetic 

 cord in various positions, and of the lower cervical and 

 upper dorsal rootlets, concluded that the vaso-constrictor 

 fibres for the upper limb leave the cord through the mid- 

 dorsal roots, thence travel to the ganglion-stellatum, and so 

 by its rami reach the cords of the brachial plexus. 



With regard to the vaso-motor fibres to the trunk, 

 Langley* finds that, in the main, they are the same as the 

 origin of the pilo-motor fibres, though their distribution for 

 any particular ramus is as a rule rather more extended than 

 that of the latter from the same ramus. 



^ Journ. of Physiol.., vol. xii., p. 373, 1891. 

 ^ Ibid..) vol. xvii., p. 307, 1894-5. 

 ^ Leip. £er., vol. xx., p. 73, 1868. 

 ^ Loc. cit., p. 312. 



