274 Susajina Phelps Gage 



IV. Though small in the adult, this nerve is clearly seen 

 (Fig. 26). In the larva a few cells (Fig. 84), probably indi- 

 cate its rudiment, for in the next older stages it can be found. 

 In the adult, the 3d and 4th nerves escape from the skull by 

 separate foramens (Fig. 3). In the larva only one foramen 

 through the cartilage is seen, and through this the 3d leaves 

 the brain. Kingsley (30) did not find this nerve in larval am- 

 phiuma. 



V. This has its origin at the usual place ventrad of the 

 lateral recess of the epencephal (Fig. 39, 40, 25). Figure 44 

 shows fibers arising near the origin of the 3d, which extend 

 to and unite with the fibers of the 5th. In the larva this 

 nerve and the lateral recesses are far cephalad (Fig. 6, 82). 



VI. The origin of this nerve is caudad of the 8th and upon 

 the ventral side (Fig. 63). It is very small even in the adult 

 (Fig. 25), but can be traced latero-cephalad to its union with 

 the gasserian ganglion. In the larva only a mere trace of it 

 was distinguished (Fig. 85) at its origin. This nerve is in 

 amphibia so small as to escape observation, or it is variable in 

 position. Kingsley (30) says it is not found in larval am- 

 phiuma ; Rei.ssner (42) shows it in the frog ; Ecker (9, p. 

 149) figures it at the level of the loth in the frog ; Fischer (13) 

 in siredon near the 7th ; Osborn omits it entirely from some 

 of his figures. 



VII. VIII. In the adult these two nerves are very closely 

 connected, as are their ganglia. The 8th, however can be 

 said to be cephalo-ventrad of the 7th at its origin (Fig. 3-5), 

 and comprises fibers only (Fig. 26), .some of which cross the 

 meson. The 7th at its origin has a great dorso-ventral 

 extent, the more dorsal part extends from the sulcus (p. 291) 

 (Rautenlippe of His), existing between the solid and mem- 

 branous portion of the metencephal, and is cellular in character. 

 The more ventral part consists of fibers (Fig. 8). There is no 

 space between the fibers of the 7th and 8th, which pass 

 into the united ganglion. In the larva the origin of the 7th 

 and 8th are quite separate ; the cellular portion of the 7th 

 is continuous with the cinerea about the sulcus on 

 the one hand and' the ganglion on the other ; while the 



