willard: cranial nerves of anolis carolinensis. 51 



by any writer to a muscle innervation similar to the one above de- 

 scribed. This peculiarity, coupled with the described function (p. 

 33) of this muscle, offers a problem for comparative study. It is 

 to be noted that no ganglion cells were found at the point of union 

 either on V or VII. 



Afferent neurons. The central course of these fibers is so involved 

 in other brain tracts that the present description will begin at the 

 superficial origin of the root. The descending root of the trigeminal 

 nerve traced cephalad approaches the surface of the medulla and 

 produces a swelling of the surface beneath the roots of nerves VII and 

 VIII (Plate 6, fig. 18, rx. V). The motor neurons, as before described, 

 join this bundle rather abruptly from a more median position, and the 

 two together leave the brain as a single root. The fibers making up 

 the sensory components of the trigeminal lack uniformity of size and 

 medullation. They are, however, of a size approximately that of the 

 motor components of the trigeminal and facial, but also have among 

 them both larger and smaller fibers. A characteristic feature of the 

 cross sections is the presence of a few very large, strongly medullated 

 fibers. These are recognizable in the brain, and a central connection 

 may possibly be established for them. Peripherally they seem to 

 offer no special relation to end organs. They occur in limited num- 

 bers and are always scattered as isolated fibers. It is possible they 

 are motor in their character and are transferred to the motor rami. 



The ophthalmic, maxillary, and mandibular divisions of the trigemi- 

 nal are recognizable even proximal to the ganglion {gn. V; gn. opth.), 

 the two ganglia being entirely distinct and scarcely in contact in 

 series 30. The relative sizes and positions of the ganglia are best seen 

 from the figures on Plates 2, 3. The cross section (Plate 6, fig. 17) 

 shows the segregation of the two cell groups. In addition to these 

 two ganglia, one of the figures (Fig. 6) shows a third ; a very small ven- 

 tral group of cells entirely similar in the sections to those of the larger 

 ganglia. Careful study was made of this small ganglion to discover 

 any structural features that would indicate a sympathetic character, 

 but comparison showed no such group on the opposite side of the 

 same individual ; in this case therefore it is probably a separation (in- 

 constant) of a few cells of the main ganglion. From what we know 

 of other forms, it seems probable that the sympathetic rami of the 

 lachrymal plexus send fibers to the Gasserian ganglion, but that could 

 not be demonstrated in Anolis, and there is no deep sympathetic trunk 

 connecting the Gasserian with more posterior ganglia. 



A detailed account of the peripheral distribution of the sensory 



