On the Nerve-fibres which produce Contraction of the Spleen. 287 



February 27, 1896. 



Sir JOSEPH LISTER, Bart., President, in the Chair. 



A List of the Presents received was laid on the table, and thanks 

 ordered for them. 



The following Papers were read : — 



L " On the Spinal-root Connections and Ganglion-cell Con- 

 nections of the Nerve-fibres which produce Contraction of, 

 the Spleen." By E. A. Schafer, F.R.S., and B. Moore. 

 Received February 12, 1896. 



(From the Physiological Laboratory of University College, London.) 



We have investigated, in fonr dogs, the effects npon the spleen 

 volnme of excitation of the thoracic and lnmbar nerve-roots. In all 

 four cases the animals were fully anaesthetised, at first with chloro- 

 form and afterwards with morphia, and were curarised, artificial 

 respiration being maintained in the usual way. The spinal cord was 

 then exposed in the dorso-lumbar region, and the nerve-roots on both 

 sides tied and cut close to the dura mater, the latter with the enclosed 

 portion of cord being then entirely removed. The blood pressure 

 in the aorta was recorded by a tube tied into the carotid artery and 

 connected with a mercurial manometer, and the spleen volume was 

 simultaneously inscribed by a tambour connected with the spleen 

 plethysmograph (see preceding paper, p. 229). 



The following are the results which we have obtained from exci- 

 tation of the nerve-roots from the second postcervical to the fifteenth 

 postcervical inclusive. In none of the four experiments did excita- 

 tion of the second postcervical (second dorsal) pair produce any 

 contraction of the spleen. In none of the four experiments did 

 excitation of the fifteenth postcervical pair produce any contraction 

 of the spleen. In three out of the four experiments a distinct 

 contraction of the spleen was got on stimulation of all the roots on 

 both sides from the third postcervical to the fourteenth postcervical 

 inclusive. This effect was relatively smaller on stimulation of the 

 third and fourth postcervical nerves and of the eleventh to the four- 

 teenth postcervical than on stimulation of the intermediate pairs, the 

 most marked effects being obtained from the sixth, seventh, and 

 eighth pairs (compare tracings 1 and 2). In all cases the effect was 



