2l6 NERVE COMPONENTS OF BONY FISHES. 



The infra-orbital trunk is a fusion of four nerves which 

 in some vertebrates are distinct. These are, (i) the r. 

 mandibularis V, with general cutaneous and motor com- 

 ponents, (2) the r. maxillaris V, general cutaneous, (3) 

 the r. buccalis, lateralis, and (4) communis fibres to taste 

 buds of the upper lip, which apparently correspond to the 

 n. rostri interni (Stannius) of Acipenser. 



The supra-orbital trunk is a fusion of the r. ophthal- 

 micus superficialis VII, for the supra-orbital lateral line, 

 communis fibres of uncertain distribution, and the r. 

 ophthalmicus superficialis V, general cutaneous. The 

 latter nerve must not be confused with the r. ophthal- 

 micus profundus, as several of the most recent writers 

 have done. The profundus nerve is apparently repre- 

 sented by a vestigeal bundle of general cutaneous fibres 

 which run out from the Gasserian ganglion with the radix 

 longa of the ciliary ganglion. 



The r. oticus is the dorsal ramus of the facialis segment 

 and was probably originally a general cutaneous nerve to 

 which a lateralis element has been added. Its general 

 cutaneous portion has secondarily fused with the Gasserian 

 ganglion. 



The r. lateralis accessorius corresponds to the r. recur- 

 rens V, or superficial lateral line nerve, of the older 

 authors. It is composed exclusively of communis fibres 

 and, after receiving other communis roots from the vagus 

 complex, seems to innervate the row of terminal buds 

 under the dorsal fin. 



Section 8. — The Sympathetic Nervous System. 



The sympathetic system has not been exhaustively 

 studied, as the work of previous investigators has covered 

 the ground quite satisfactorily so far as it can be done 



