222 



J.-N. LANGLEY 



effects are obtained in the dog on stimulating of the central end of one limb 

 of the annulus of Vieussens, after the connection of the ganglion stella- 

 tum with the spinal cord hâve been severed. Thus he found dilation of 

 the pupil, contraction of the arteries of the ear, the sub-maxillary gland 

 and the nasal mucous membrane, and accélération of the heart. He 

 considered thèse effects to be true réflexes from the ganglion stellatum, 

 produced by afférent fibres running to the nerve-cells of this ganglion. 

 There are two points hère to consider, first what effects are obtainable 

 from the central end of the annulas of Vieussens when the ganglion stella- 

 tum is not connected with the spinal cord ; and secondly if any eff"ects are 

 obtained what is the mechanism by which they are produced. I hâve 

 made eight experiments upon anaesthetized cats ; the results are given in 

 the following table. The experiments are not arranged in the order in 

 which they were made. 















haïr 





EXP. 



LIME. 



of vieus. 



OF ANN. 



stimulated. 



NICTITATING 



membrane. 



EYKLIDS 



PUPIL 



of face 

 andback 



BLOOD 



vessels. 















of head. 



of ear. 



I. 



Right 



ventral. 















— 



— 



II. 



Left 



ventral. 















— 



— ■ 



III. 



Left 



ventral. 



















— 



IV. 



Left 



ventral. 



















— 



V. 



Left 



ventral. 























VI. 



Left 



dorsal. 























VIL 



Left 



ventral. 



slight. 



slight. 







— 



— 



nu. 



Right 



ventral. 



moderate. 



moderate. 















ïhe conspicuous feature of the results is the absence of reflex effect. 

 In every case the central end of the limb of the annulus of Vieussens was 

 repeatedly stimulated. In every case stimulation of the end of the thoracic 

 sympathetic just below the ganglion stellatum produced at once sharp 

 retraction of the nictitating membrane, séparation of the eyelids, dilation 

 of the pupil, and complète pallor of the ear; so that the absence of effect 

 on stimulating the central end of one limb of the annulus of Vieussens 

 was not due to any injury of the ganglion stellatum or of the other limb ot 

 the annulus. 



It need perhaps hardly be mentioned that if the white rami Connecting 

 the ganglion stellatum with the spinal cord are not severed, stimulation of 

 the central end of one limb of the annulus of Vieussens readily causes 

 dilation of the pupil, retraction of the nictitating membrane and opening ot 

 the eye; it causes somewhat less readily pallor of the ear. I hâve not 

 observed that it causes any érection of hairs. In profound anaeslhesia, thèse 

 effects may be obtained without any body-reflex though much more slowJy 

 and less perfectly. It is known also that thèse effects can be produced by 



