8 OLOF LAESELL 



these fibers with those of the nervus terminaHs was not clearly 

 demonstrated. The fiber groups were lost in the brain substance 

 without evidence of definite terminations, though the fascicles 

 reaclj backward into the mesencephalon (hypothalamus and 

 interpeduncular region), a condition not yet noted in other 

 forms. Peripherally are ganglion cells with fibers going appar- 

 ently to the nasal capsules. 



C. Judson Herrick ('17), in connection with other studies, 

 has completely confirmed in Necturus the findings of McKibben. 



Reptilia. Among reptiles the nervus terminalis has been 

 found by Johnston ('13). In a paper, which embraces also a 

 consideration of the nerve in pig, sheep, and human embryos, 

 he describes the terminalis in embryos of the turtle (Emys 

 lutaria). In Emys the nerve emerges from the rostral end of 

 the median wall of the brain hemisphere, caudal to the olfactory 

 bulb. From this point ''It descends over the medial surface of 

 the bulb and olfactory nerve and bears clumps of ganglion cells 

 at several points of its course. It comes into close relation with 

 the dorsal division of the olfactory nerve, but is distinguished 

 from it." Peripherally the fibers of the nervus terminalis are 

 distributed with those of the dorsal division of the olfactory 

 nerve to the extreme lateral portion of the nasal sac, which is 

 interpreted by Johnston to correspond with the vomeronasal 

 organ of mammals. 



According to McCotter ('17), the dorsal division of the olfac- 

 tory nerve of the turtle is to be considered homologous with the 

 vomeronasal nerve of mammals, and the dorsal portion of the 

 formatio olfactoria of the bulb, as illustrated in Johnston's fig- 

 ure 11, corresponds to the accessory olfactory bulb of mammals. 



Birds. Whether or not the ganglion cells observed by Ruba- 

 schin ('03) in the chick embryo represent cells of the nervus termi- 

 nalis is problematical. This writer describes a ganglionic mass 

 related on the one hand to the trigeminus nerve and on the other 

 to the olfactory mucosa. Axones from this mass were traced 

 to the Gasserian ganglion. Two types of cells were found in the 

 ganglionic knots: 1) bipolar cells resembling those of the inter- 

 vertebral ganglia, and 2) multipolar cells with numerous proc- 



