246 ALUS. [Vol. XVIII. 



and in part from the medulla immediately ventral to that struc- 

 ture. It received from the acusticus, in one dissection, a communi- 

 cating strand which first touched and anastomosed with the ventral 

 part of the posterior trigemino-facial root and then continued on- 

 ward and joined the dorsal, or lateral line, part of the root. This 

 strand was not noticed in other earlier dissections, but might have 

 easily been overlooked. The two trigemino-facial roots both run 

 forward, laterally, and slightly downward, and fuse more or less 

 completely with each other while still inside the cranial cavity. 

 They are completely hidden, in dorsal views, tmder the overhang- 

 ing optic lobe. 



The posterior root always shows three somewhat distinct tracts 

 of fibers, and these tracts can, in certain preparations, be separated, 

 at their origin from the brain, as three distinct bundles. Two of 

 these three roots, or bundles of fibers, lie ventral or ventro-lateral 

 to the other one, and they always fuse quite completely with each 

 other and with the anterior, trigeminal root of the complex, while 

 still inside the cranial cavity. The dorsal root, or bundle, always 

 remains much more distinct from the other three roots of the com- 

 plex than either of the latter three does from the others. From it 

 the ophthalmicus facialis, buccalis facialis and oticus facialis have 

 their apparent origins. Whether the fibers that form the mandi- 

 bularis externus facialis also arise from it, or arise as a part of 

 one of the other three roots of the system could not be deter- 

 mined. The most posterior and ventral of the other two bundles 

 of the posterior root of the complex seemed to pass entirely to the 

 hyoideo-mandibularis facialis and hence to be the motor facial root 

 of the complex. The remaining root or bundle was distributed to 

 both the facial and trigeminal branches of the complex. This latter 

 root .would seem to be the one described by Stannius (No. 70, p. 

 32) as the third root of the complex, and said by him to have a 

 separate or nearly separate ganglion formed upon it. 



The trvmk formed by the more or less complete fusion of these 

 several roots or bundles, becomes ganglionic while still inside the 

 cranial cavity, and separates into two portions. One of these 

 portions turns backward and laterally and traverses the facial 

 foramen through the petrosal, the other continuing forward and 

 laterally in the general line of the trunk and traversing the tri- 



