196 Journal of Comparative Neurology. 



From the relations as presented by von Plessen and Rabinovicz 

 in Salamandra, this would appear to be the dorsal root of the 

 trigeminus as well, since in that species not only is this dorsal 

 root quite distinct from the ventral, but since also its cephalic 

 branch does not enter the Gasserian ganglion, giving rise di- 

 rectly to the r. frontalis and the r. maxillaris trigemini. Strong, 

 however, regards both branches of this dorsal root in Ambly- 

 stoma as facial [8, Part 2,] while Stieda [7] figures in Axolotl 

 the whole of the facial as entering the Gasserian ganglion and 

 seems to regard the free portion as wholly auditory. For a 

 further discussion of these homologies consult the paragraphs 

 devoted to the r. fronto-maxillaries trigemini. 



The acustico-facial ganglion lies partly within and partly 

 without the otic capsule. It is plainly separable into a caudal 

 acustic and a cephalic facial portion. Neither portion is large 

 and the ganglion cells are scattered far out on the diverging 

 rami. Both portions pertain almost wholly to the ventral root ; 

 for, although the dorsal root contributes about half of its fibres 

 to the cephalic ramus of the ventral root, yet these fibres have 

 but few ganglion cells among them, most of them arching 

 around to the ectal aspect of the ganglion, thence to enter the 

 seventh nerve without mingling with the fibres destined to end 

 within the otic capsule. 



The ventral root divides at the ganglion into a cephalic or 

 utricular ramus and a caudal or saccular ramus. The caudal or 

 saccular ramus first sends a large branch directly laterad and ven- 

 trad to be distributed over the macula acustica sacculi, the 

 ramulus acusticus siiccidi (r. a. s). From it there then descend 

 the ramulus acusticus lagencs {r. a. I.) and the ramulus acusticus 

 basilaris (r. a. b.) to their respective papillae. At about the same 

 transverse level the ramulus acusticus neglcctus (r. a. n.) ascends to 

 the macula neglecta. The remaining fibres of this ramus pass 

 back to the crista acustica posterior at the caudal extremity of 

 the membranous ear, thus constituting the ramulus acusticus 

 posterior (r. a. p.). 



The cephalic ramus may be regarded as the combined 

 trunks of the ramus acusticus uhiculi and the netvus facialis. It 



