THE R. LATERALIS ACCESSORIUS. 203 



sensory V root dorsally. Just caudad of the point where 

 the f.bres of the dorsal lateral line root diverge toward their 

 respective trunks this dorsal bundle of communis fibres 

 sends off the second recurrent root {rcc. 2). This root is 

 then re-enforced by a strand of communis fibres from the 

 vertral bundle. It goes directly dorsad into the meninges 

 covering the optic lobe. Here it breaks up into several 

 small twigs, the largest of which continues caudad to join 

 the first root before it leaves the cranium. Another twig 

 runs in the meninges farther dorsad, where it is joined by 

 a small twig from the third root of the r. lateralis acces- 

 sorious, and after the anastomosis it at once sends a twig 

 dorsad through a foramen in the cranial roof. The ter- 

 minus of this twig was lost by imperfections in the sec- 

 tions. I find, however, on the opposite side of the same 

 specimen a naked sense organ in the corresponding posi- 

 tion, which is doubtless supplied by this nerve. The 

 remaining fibres of this anastomosing twig run to a fora- 

 men in the roof of the cranium farther caudad and 

 probably join the first recurrent root extra-cranially. 



The third root of the r. lateralis accessorius {rec, j) 

 arises immediately cephalad of the second and close be- 

 hind the origin of the r. oticus. It contains very fine 

 fibres and a considerable number of slightly larger and 

 more heavily myelinated fibres. The latter arise from 

 the dorsal communis bundle. Near its origin and em- 

 bedded among its fibres is a cluster of five or six small 

 ganglion cells. They belong to the finer fibres, and these 

 enter the V + VII ganglionic complex farther cephalad 

 than the other fibres. In several of my series these finest 

 fibres were traced cephalad with tolerable certainty into 

 the most cephalic ganghon {sy. i) of the sympathetic 

 chain, as indicated on Fig. 4. This little ganglion is, 



