THE CEANIAL NERVES AND LATERAL SENSE ORGANS OF i'lSHES. 1G9 



discussed the supposed anastomosis of the tnie lateral nerve with the spinal nerves, he 

 decides in favour of the connection between the two. It seems to the writer, from a 

 careful examination of the various descriptions of this supposed connection, that the 

 writers concerned have been dealing with the lateral ramus of the accessory lateral nerve, 

 and have indeed found the connections they described, but mistake one of the nerves 

 they were dealing with. However this may be, it is certain that the true lateral nerve 

 never anastomoses with the spinal nerves. 



The "opercular branch" mentioned by Eaudelot (1869, 14) in various Cyprinoids 

 seems to belong to the accessory lateral system, since it arises partly from the vagus 

 and partly from the " trigeminus," <ind moreover has a cutaneous sensory distribution. 

 Friant (1879, 73) describes the origin of the recurrent facial in Cyprinoids and " Barhus 

 fliwiatiUs''' { = Barbus vulgaris) in terms that practically amount to a brief antici^iation 

 of Pollard's work. He also describes and figures the accessory lateral nerve in many 

 bony fishes, including " Gad us cai-honarius'' (pi. v.) and '^ Gadus lota" (j)l. vi.), the 

 latter showing the system and its anastomoses with the spinal nerves especially at the 

 pelvic fin branches. 



Emery (1880, 66) describes the accessory lateral nerve in Fierasfer as folloA\s (p. 36) : 

 " n ranio laterale del trigemino e ridotto ad un sottilissimo filamento, il quale corre 

 sotto la volta del cranio e fuoriesce dietro il margine posteriore del parietale, per 

 continuarsi, senza ramificazioni, sotto i niuscoli della pinna dorsale ; non ho veduto 

 anastomosi di questo nervo col vago." The accessory lateral of Fierasfer is thus an 

 exceedingly simplified edition of the Cod type. Baudelot, in his posthumous monograph 

 (1883, 16), rediscusses an anastomosis he had previously described (1868, 13) between 

 the vagus and the "trigeminus." He now compares it with the recun-ent facial of 

 Cyprinoids, but from his description and figure he must undoubtedly have been dealiu'i- 

 with a lateral line anastomosis such as that described by Pinkus in Protopterits. This 

 exj^lanation is further suggested by the fact that his anastomosis communicated with 

 the auditory nerve. PI. iii., figs. 12 & 13, show a curious origin of the accessory 

 lateral nerve in Lota vidgaris if correct *. The posterior root, Avith its two vagal rootlets, 

 is fairly normal, but the anterior root is formed by the union of a small and laro-e 

 rootlet, both of which arise from the trigemino-facial ganglionic complex. These two 

 rootlets doubtless sjiriug one from the trigeminus and the other from the facial — much 

 as in Cypjriiius carpio (Haller). Baudelot figures (pi. v. fig. 3) the roots of the system 

 in the latter fish, but I propose to rely on Haller's account of them. E-amsay WrifTht 

 (1884, 228) states that the "Ramus lateralis trigemini" is connected with the first, 

 second, and third spinal nerves, " and acts as a collector for slenderer branches from all 

 the other rami dorsales " (Amim-iis), and further that the bulk of its fibres is derived 

 from the fine-fibred root of the facial. Fritsch (1887, 75) very briefly mentions the 

 system as the " nervus lateralis trigemini." 



In the Sole, the nerve that seems to me to correspond to the accessory lateral of the 

 symmetrical fishes is, as one would expect, in a very interesting condition. Cunnino-ham 

 (1890, 55) says: — "The right dorsal branch of the fifth, after its upward course on the 



* Not confirmed by Goronowitsch (1S97, 90). 



