Il6 NERVE COMPONENTS OF BONY FISHES. 



of the cases at least, general cutaneous fibres, his account 

 may be introduced here. He finds it to contain both 

 coarse and fine fibres, from the lateralis root and the chief 

 vagus root respectively, but no motor fibres, as shown by 

 the negative results of stimulation. In this latter point 

 he differs from Baudelot, as we saw above. Stannius adds 

 that the intra-cranial branch is absent in Scomber, Pleuro- 

 nectes. Rhombus, Salmo, Coregonus, Ammodytes, Clupea, 

 Silurus, Spinax and Raja. It is present in Perca, Acer- 

 ina, Cottus, Trigla, Barbus, Caranax, Zoarces, Cyclop- 

 terus, Labrus, Belone, Gadus, Merlangus, Raniceps, Lota, 

 Cyprinus, Abramis, Gobio, Tincta, Esox, Acipenser and 

 Anguilla. Now Perca, Acerina, Cottus, Zoarces, Cyclop- 

 terus, Labrus, Belone, Gadus and Anguilla possess a r. 

 recurrens V [VII] and this intra-cranial branch anasto- 

 moses with it. Stannius states that all forms which have 

 a r. recurrens V [VII] also possess this intra-cranial 

 branch, with the single exception of Silurus. He de- 

 scribes the intra-cranial branch also in those fishes which 

 have a dorsal intra-cranial or cranial branch of the V [VII] 

 nerve, with which it usually anastomoses, as in most cy- 

 prinoids. Or it may pursue an independent course to the 

 skin, as in Barbus and Caranax trachurus, or to the men- 

 inges, as in Esox. It occurs, finally, in cases where there 

 is no recurrens V [VII] and distributes mainly within the 

 cranium, as in Trigla and Acipenser. 



In the species enumerated by Stannius as lacking the r, 

 cutaneous dorsalis it will probably be found that the nerves 

 are so small and sinuous as to have eluded discovery. 

 The anastomosis with the r. recurrens V [VII], or r. later- 

 alis accessorius, described by Stannius and Baudelot prob- 

 ably pertains to a communis component of the cutaneous 

 nerves. A similar anastomosis occurs in Menidia, though 

 in this case the communis fibres go out with the r. supra- 

 temporalis rather than the cutaneous rami. See the 

 account of the r, supratemporalis vagi below for further 

 discussion of the morphology of these nerves, and Section 

 1 2 for discussion of the anastomoses with the r. lateralis 

 accessorius. 



