272 NERVE COMPONENTS OF BONY FISHES. 



dorsalis. In its intra-cranial course it is intimately related 

 to the origin of the r. lateralis accessorius, but no inter- 

 change of fibres could be demonstrated. 



p . — The Oculoniotoriiis. 



The third nerve, like the fourth, is a pure somatic 

 motor nerve. The origiu is essentially as in the last case 

 and the nerve peripherally has no connections with any 

 other nerve save with the ciliary ganglion. 



III. — Review of the Cranial Components. 

 /. — TJie General Cutaneous System. 



Under this head I have included all nerves, exclusive 

 of the sympathetic, which terminate free in the skin 

 without specialized end organs. These are mainly nerves 

 of the tactile sense, but others are also doubtless included 

 and this system v/ill ultimately have to be broken up into 

 several sensory systems. In the head this system includes 

 the two general cutaneous ganglia, the Gasserian and 

 jugular ganglia, the root fibres from these ganglia, 

 including the spinal V tract, and the terminal nuclei of 

 these root fibres, viz., the chief sensory nucleus of the V 

 nerve and the nucleus funiculi. The secondary tracts 

 from these nuclei I have not studied exhaustively. They 

 should also be included in a full account of the system. 



The morphology of this system is perfectly simple. It 

 corresponds to the sensory system of the dorsal horns of 

 the spinal cord. It has suffered less modification in the 

 head than any of the other systems, the most important 

 being its suppression in all but the V and X cranial nerves. 

 If it survives in any of the other nerves, it is in so altered 

 form as to be unrecognizable. See Section 3, I ; Section 

 5, I, 3 and VIII; Section 7. 



