Scientific Proceedings. 



99 



hand, reported, about one year before Langendorff, an experiment on 

 a cat in which twenty -three months after the removal of the superior 

 cervical ganglion stimulation of the cervical sympathetic did not pro- 

 duce the usual effects, and on microscopical examination some 

 postganglionic nerve fibers were found to have been regenerated ; 

 but there were neither nerve cells nor any union between the post- 

 ganglionic and preganglionic nerve fibers. Later Langley and 

 Anderson 1 repeated the experiment on eight cats. In six of the 

 animals, which lived between one hundred and eighty-three and 

 four hundred and seventy-six days, the paralytic symptoms 

 remained permanent, and stimulation of the cervical sympathetic 

 caused no effect. In two of the cases there was some decrease in 

 the paralytic symptoms, and stimulation of the cervical sympathetic 

 caused some effect, but microscopical examination showed that in 

 both cases not all of the nerve cells had been removed. 



All the above experiments were made on cats, which have a 

 large ganglion. The gap between the postganglionic and pre- 

 ganglionic nerve fibers in the cat is nearly one centimeter. In the 

 rabbit the ganglion is barely three millimeters long, and there 

 might perhaps be a better chance for a final union of the nerve 

 fibers of the two poles of the ganglion. I am going to report here 

 briefly some observations made on a rabbit which lived over thirty 

 months after the removal of the superior cervical ganglion. 



Full grown, grey, male rabbit. Left superior cervical gang- 

 lion removed October 14, 1904. Animal died April 23, 1907. 



Soon after the removal of the ganglion the left pupil became 

 quite small ; a few days later it became somewhat wider again, 

 and some weeks later it became constricted to about the original 

 size after the operation and retained this size permanently until 

 death. The blood vessels of the left ear, which became wider 

 after the removal of the ganglion, gradually assumed the size of 

 the vessels of the other ear and remained in that state perman- 

 ently. During the last eighteen months the blood vessels of both 

 ears were never very wide and showed but little of the usual rhyth- 

 mical changes. 



We 2 have shown that after removal of the ganglion, a sub- 



1 Langley and Anderson : Journal of Physiology , xxxi, 383, 1904. 



2 S. J. Meltzer and Clara Meltzer Auer : American Journal of Physiology , xi, 28, 

 1904. 



