294 Journal of Comparative Neurology. 



The sympathetic ganglia of the trigemino-facial region 

 corresponding to the first, second and third ganglia of Menidia 

 and some other fishes are here fused into a single elongated 

 ganglionated strand, which follows the course of the orbital 

 vein. This wide vein or sinus, runs along the inner side of 

 most of the trigemino-facial complex between the third nerve 

 above and the sixth nerve below. 



The sympathetic chain runs from the IX + X root com- 

 plex extra-cranially parallel with Jacobson's anastomosis, though 

 without fusing with it, to the V + VII root complex, as already 

 described (Figs. 2, 3, 4, sj/.). Just behind the trigemino-facial 

 foramen it expands into a large ganglion (Fig. 5, sy.) This 

 ganglion runs up into the foramen (Figs. 6 and y, sy. g.) and 

 in the narrow space under the emerging ventral lateralis root 

 is crowded in with the orbital vein, the motor VII and the 

 communis fibers for the r. pre-trematicus VII and Jacobson's 

 anastomosis. These nei-ves are all very intimately mingled. 

 The communis fibers last mentioned pass out directly through 

 the middle of the sympathetic ganglion, though the Weigert 

 sections leave no doubt that these fibers do not arise in the 

 sympathetic ganglion. The motor fibers for the m. adductor 

 arcus palatini pass out close to these, curving around the dorsal 

 and outer side of the ganglion. 



Having passed inside of the foramen, the sympathetic gan- 

 glion becomes reduced to a narrow strand of cells with many 

 fibers. This strand passes around the outer side of the blood 

 sinus from its ventral to its dorsal side (Fig. 8, sy.) internal to 

 the emerging infra-orbital trunk. It then turns cephalad (from 

 this point on non-ganglionated) along the dorsal side of the 

 blood vessel and under the forward extension of the Gasserian 

 ganglion for the r. ophthalmicus superficialis V. As we pass 

 cephalad, this blood vessel divides into two and the sympathe- 

 tic nerve runs between its two divisions and joins itself to the 

 dorsal surface of the III nerve (Fig. 9, sy.) Its further course 

 has been partially worked out. It follows the still undivided 

 III nerve forward and after that nerve has given off its branch 

 for the m. rectus superior the sympathetic accompanies the 



