86 'Journal of Comparative Neurology and Psychology. 



that the glossopharyngeus and vagus, at least in Lophius and 

 Gadus, have no descending fibers, from which it results without 

 doubt that the part of the nucleus vagi of higher animals, which is 

 situated more spinalward and receives the terminations of root 

 fibers has been taken up in the lobi themselves which are conse- 

 quently better developed. The commissura infima in teleosts, 

 as far as I was able to ascertain, contains only secondary decus- 

 sated communis fibers, of which such as originate behind might 

 be considered as fibers of the nucleus commissurae infimae (Fig. 

 Ixxx, Plate V). 



Another secondary system of the vagus has been already slightly 

 noticed. It consists of small, compact medullated uncrossed 

 bundles which run from the communis region ventrad to a position 

 mesially of the tr. descendens N. quinti. They then turn forward 

 along this tract and continue in the same direction after the sepa- 

 ration from the brain of the sensory root of the trigeminus and 

 terminate in an important enlargement between the cerebellum 

 and the oblongata, the nucleus lateralis cerebelli, which has been 

 described above. This is the secondary communis tract which 

 has been described by Mayser, as "secondary vago-trigeminus 

 tract," and also by Haller, Kingsbury and Johnston. May- 

 ser called it the "Rindenknoten" and Johnston "secondary 

 nucleus vagi" after the tract which ends here. But since there 

 are other fibers which begin or end here, I prefer to use a more 

 general term, "nucleus lateralis cerebelli," the name given to it 

 by Edinger for the selachians. These nuclei of the two sides are 

 connected by a commissure, the com. inferior cerebelli (Fig. Ixxxvi, 

 Plate VI), or as Johnston calls it, the "secondary vagus com- 

 missure." 



These, however, are not all of the secondary communis connec- 

 tions. First, I mention a small group of fibers which relate the 

 communis region with the acusticum and perhaps wnth the cere- 

 bellum, a connection which Johnston seems also to have observed 

 in Acipenser. Secondly, there is a tract from the sensory vagus 

 nucleus running in the fasciculus dorsalis and appearing to ter- 

 minate in the contra-lateral nucleus, of which, however, I cannot 

 be sure (Fig. xcix, Plate VII). 



As for the motor glossopharyngeus and vagus fibers, I may 

 briefly note that they pass from their source, the nucleus amhiguus, 

 partly without decussation and partly decussated through the 



