48 bulletin: museum of comparative zoology. 



As compared with this, we find in Anolis the following differences : — 

 (a) nerve V connects directly with the ciliary ganglion by a branch 

 which contains a large proportion of medullated fibers; (b) the non- 

 medullated components from the trigeminal are carried in the large 

 ciliary nerve and form no small non-medullated rami ; (c) the ganglion 

 is not divisible into two parts and has more the appearance of a cerebro- 

 spinal ganglion. It should be noted, however, in regard to this last 

 point (c), that the complete Vom Rath method was not used in the 

 preparation of the Anolis material, the treatment with pyroligneous 

 acid being omitted. This omission may have resulted in less differen- 

 tiation within the ganglion and a consequent failure to discover the 

 differences recorded by Carpenter. 



M. TRIGEMINAL NERVE. 



The afferent and eft'erent neurons that go to make up the mixed 

 root of nerve V form one large bundle, in the cross section of which 

 there is shown no segregation of components at the point of emergence 

 from the brain. More centrally, however, the main sources of these 

 components may readily be found. More complete study of the 

 brain will no doubt result in some addition to this account of peri- 

 pheral structure and possibly to some revision. The central relations 

 of the neurons are here referred to briefly and only in so far as they were 

 brought out in the series of sections from which the plottings were 

 made. 



The efferent neurons. The motor components were seen, in sec- 

 tions posterior to the superficial origin of the root, to arise from two 

 sources : (a) a group of cells lying a short distance mesad and slightly 

 dorsad to the connection of the root with the brain, and (b) from a 

 region just laterad to the median longitudinal fasciculus. From both 

 these sources the bundles of heavily medullated fibers pass directly 

 out to the ventro-median part of the root. Here they form with the. 

 afferent components a common root-bundle, in which it is difficult 

 to distinguish the two. At the point of superficial origin the mixed 

 root-bundle is covered dorsally by the ganglion of nerve VIII (Plate 6, 

 fig. 18, rx. V; gn. VIII). The root passes cephalad between the 

 prootic bone and the skull to the Gasserian ganglion (Plate 6, fig. 17, 

 gn. V), which lies in the foramen prooticum (Gaupp). The foramen 

 is represented in the skull of Anolis by a notch in the anterior })order 



