ELECTKICAI.LY STIMUI-ATED GANGLION CELLS. 17 



pulse and respiration, should result. The operation is 



performed while the animal is under slig;ht anaesthesia j 



from ether. The right brachial plexus is then laid 1 



bare in the axilla, and, with great care as regards 1 



injuring the nerves or blood-vessels going to them, ] 



freed from fat and disentangled from the subclavian | 



artery and vein, so that these may not be included ] 



between the electrodes. By including the whole plexus j 

 at this point, four ganglia are stimulated. My own 



practice has been to slip a two-tined platinum electrode 1 



over the plexus from behind, in such a way that the ' 



two tines of the electrode touch opposite sides of the I 

 nerves and make it necessary for the stimulus to pass 



obliquely through them. The greater number of the | 



fibers, however, from the 6th and 7th cervical escape ] 



stimulation, and possibly, too, the nerves from the I 

 1st dorsal and 8th cervical coming first between the 

 electrodes, tends somewhat to short circuit the current, 



thus depriving the other nerves of an equal share of ' 



the stimulation. At any rate, the 6th and 7th cervical j 



have failed to show the effect of stimulation to the ' 



extent that the 8th cervical and 1st dorsal do. Hence j 

 for the clearest results it is best to include in the 



circuit only the medius and spiralis nerves and the , 



branches lying behind these, and then use only the \ 



8th cervical and 1st thoracic ganglia. A double control j 



was employed at first, consisting of thoracic ganglia I 



from the same animal, a pair of these being carried j 



through with each pair of test ganglia. This was soon ' 

 found to be entirely unnecessary, since the cells of 



these control ganglia invariably resembled those of the I 



resting ganglion. ; 



Table V. j 

 Cat No. 1. Stimulated for 7 hours; intervals, one 

 minute. 



