ioo Society for Experimental Biology and Medicine. 



cutaneous injection or an instillation of adrenalin into the con- 

 unctival sacs of the rabbit causes a dilatation of the pupil on the 

 side from which the ganglion was removed. This biological test 

 for the absence of the ganglion was frequently made within the two 

 and a half years of the animal's life and it was found that a sub- 

 cutaneous or intramuscular injection or an instillation of adrenalin 

 invariably caused a long lasting dilatation of the left pupil. This 

 test seemed to prove satisfactorily that the ganglion was not re- 

 generated, or at least the postganglionic and preganglionic nerve 

 fibres did not grow together. To obtain further proof, twenty- 

 eight months after the removal of the ganglion the cervical sym- 

 pathetic nerves of both sides were exposed and stimulated with 

 induction currents. While stimulation of the right sympathetic 

 easily caused the usual effects upon the ear vessels and pupil of 

 the corresponding side, stimulation of the left cervical sympathetic 

 caused 110 changes zvhatsoever in the left pupil or in the vessels of 

 the left ear} 



During the last twelve months there were, however, a few 

 changes which deserve to be mentioned. In the first place the 

 dilatation of the left pupil never attained the same degree as dur- 

 ing the first period. Further an intramuscular injection of adrena- 

 lin, which in the early period brought out the dilatation of the 

 pupil within two or three minutes, 2 now developed its effect very 

 slowly. Finally the constricting effect of eserin was only partly 

 overcome by an injection or instillation of adrenalin, whereas in 

 the early period the effect of eserin was completely overcome by 

 adrenalin. Apparently the relations of adrenalin to the dilator 

 pupillas had somehow undergone some changes. Local stimula- 

 tion of the iris was not tested. 



I shall record the following observations without offering for 

 the present any interpretation of them. Within the last ten 

 months the right pupil was permanently distinctly larger than nor Dial 

 and responded sluggishly to light. A n injection of adrenalin brought 

 out a distinct constriction which lasted about fifteen minutes. After 

 the above mentioned stimulation of the cervical sympathetics, 

 the permanent dilation of the right pupil disappeared for about five 



1 This experiment was carried out in the presence of Drs. Flexner, Opie and 

 Carrel. 



2 S. J. Mcltzer and John Auer : Journal of Experimental Medicine, vii, 59, 1905. 



