250 yournal of Comparative Neurology and Psychology. 



While this communicating filament between the oculomotorius 

 and the trigeminus appears superficially to be wholly difi^erent 

 from anything found in Amblystoma, it actually corresponds to 

 the twig of the profundus which, in Amblystoma, comes in contact 

 with the oculomotorius only after the latter has reached the m. 

 rectus inferior, or which, in some instances, passes independently 

 into the eye under the insertion of the muscle r. inferior without 

 coming in touch with the oculomotorius. At a similar point 

 in Triton a division of the r. inferior passes into the eye. The 

 real difference, then, between Triton and Amblystoma in this 

 respect is that the inferior ciliary branch of the profundus is more 

 closely fused with the oculomotorius in Triton. 



Now the ganglion cells in question occur on both the communi- 

 cating branch from the profundus and the branch of the oculomo- 

 torius to the interior of the eye, and at various points along the 

 main branches of the oculomotorius. They are found upon the 

 r. ophthalmicus profundus at the origin of the communicating 

 branch, upon the latter between the two main nerves, or on the r. 

 inferior III just after it has received the communicating branch. 

 Of these three positions the last has cells most commonly and in 

 greatest numbers. Only in one case have I found cells on the r. 

 superior III. Commonly there is a cluster of cells in compara- 

 tively large numbers at or near the point of branching of the r, 

 inferior III to form its three terminal rami to the muscles. In one 

 specimen, however, no cells occur in this position on one side, 

 whi'e on the other side they are found here in considerable num- 

 bers. Cells are found, also, in varying numbers on the distinct 

 rami to the m. rectus inferior, rectus internus, and obliquus 

 inferior. Frequently nerve cells are found embedded in these 

 muscles and in close relation with medullated fibers of the oculo- 

 motorius. In these cases, however, I have not been able to demon- 

 strate that these cells give rise to the medullated fibers near them. 

 Occasionally nerve cells are found even in isolated positions be- 

 tween the eye-muscles, but apparently connected more or less dis- 

 tinctly with one of the rami of the oculomotorius. 



The occurrence of ganglion cells upon the distinct branch of the 

 oculomotor to the eye is subject to wide variation. In one speci- 

 men examined there is a distinct cluster of ganglion cells upon this 

 nerve and a very small connective between it and the main ramus 

 inferior of the oculomotorius. In another instance nerve cells 



