288 ENDOCRINE GLANDS 



birth to fibres which travel by way of the short ciliary 

 nerves, to end in the eyeball. 



1. The sphincter muscle of the iris (closure, myoses). 



2. The ciliary muscle (accommodation, by action upon 

 the crystaline lens) 



Such is the vegetative motor arc annexed to the oculo- 

 motor. The axial centre is the pupillary nucleus, the 

 central ganglionic fibres, the vegetative fibres contained in 

 the III, then the fibres of the short root of the ciliary 

 ganglion ; the ganglionic centre is in the ciliary or ophthal- 

 mic ganglion from which arise the ganglion organic fibres, 

 which, by way of the short ciliary nerves, reach the 

 vegetative fibres of the eye. 



The sensory arc is represented here by the sensory tract 

 of the optic nerve, but I will not go into detail of the com- 

 plete reflex arc; diagram 26 explains this sufficiently; it 

 also explains the phenomenon of Wernicke, that is, absence 

 of the pupillary reflex- when the rays of light strike the 

 blind half of a hemianopsic eye, phenomenon which is 

 symptomatic of lesions of the optic tract and one of the 

 differential points between these and central lesions. 



B. PHYSIOLOGY OF THE VEGETATIVE SYSTEM ANNEXED 

 TO THE VII CRANIAL NERVES. 6 



These vegetative fibres, arising from the lacrymal- 

 mucous-f acial nucleus follow the course of the VII nerve as 

 far as the geniculated ganglion; then, leaving this nerve, 

 follow one of its branches, the great superficial petrosal 

 nerve, then with the vidian nerve, reach the spheno- 

 palatin ganglion, where they end and communicate with 

 ganglionic cells from which fibres arise which follow the 

 various branches of the superior maxillary branches of 



the trif acial and controls the secretion of : 



. 



6 In order to better understand this paragraph and the following see Figs. 25 and 29 



