HISTOR Y OF THE INVOL UNTAR Y NER VO US S YSTEM 2 7 



ganglion by way of the lingual nerve, and the great superficial 

 petrosal, running from the facial to Meckel's ganglion, were all of 

 the nature of rami communicantes in their composition (Fig. 6, B). 



This cranial outflow of connector nerves is found in connex- 

 ion with those segmental nerve's which arise from the medulla 

 oblongata, and may receive the name of the bulbar or mesosomatic 

 outflow. 



Anterior to the mesosomatic or bulbar region we come to the 

 prosomatic region of the cranial segmental nerves, represented in 

 the voluntary nervous system on the motor side by the nerves to 

 the masticatory muscles and on the sensory side by the trigeminal 

 nerves. Here again I found an outflow of fine medullated fibres 

 in the roots of the oculomotor nerve separating out from the larger 

 motor fibres to the striated ocular muscles to pass into the ciliary 

 ganglion, from the cells of which nerve fibres arise to form the 

 short ciliary nerves, which are motor to the sphincter muscle of 

 the iris and the muscles of accommodation (Fig. 6, A). This 

 outflow of connector nerves may receive the name of the 

 prosomatic or mid-brain outflow. 



Such was the fundamental conception of the involuntary 

 nervous system which I gave in 1885 : three great outflows of fine 

 medullated fibres to peripheral motor ganglion cells, from the 

 bulbar, thoracico-lumbar, and sacral regions respectively, these 

 three outflows being roughly separated from each other by the 

 formation of the nerve plexuses for the upper and lower limbs ; 

 and in addition a smaller separate outflow from the mid-brain 

 region. 



Just as Onodi showed that the peripheral nerve cells, with 

 which the thoracico-lumbar outflow is connected the so-called 

 sympathetic cells were originally in close contiguity with the 

 cells of the posterior root ganglia of the spinal cord, and that 

 they separated and became situated more and more peripherally 

 during development ; so Kuntz and Miss Abel have shown 

 that the peripheral nerve cells belonging to the vagus system, 

 with which the bulbar outflow is connected, were originally in 

 close contiguity with the cells of the posterior root ganglia of the 

 vagus group of nerves, and that they also separated and became 

 situated more and more peripherally during development. 



We may sum up the results of this chapter as follows. The 

 evidence indicates that the involuntary nervous system is built up 



