2/2 Journal of Comparative Neurology. 



caudad than the r. alveolaris, also. There are important dif- 

 ferences, therefore, between the posterior palatine of Siren and 

 the.palatinus caudalis of Amblystoma, and it may be that they 

 are not homologous. 



IV. The Glossopharyngeus and Vagus. 

 /. — IJie Roots. 



The origin of the glossopharyngeus by a single root and 

 of the vagus by three major roots, exclusive of the lateralis 

 root, seems to be a constant arrangement in Amblystoma. In 

 essential maters, the presence of communis and motor fibers 

 in the glossopharyngeal root, and of communis, motor and 

 general cutaneous fibers in the vagus roots, in addition to a 

 distinct lateralis root, Amblystoma agrees with Rana (Strong), 

 Necturus (Kingsbury) and Spelerpes (Bowers). 



Kingsbury ('95) doubts the relation of the most posterior 

 root of the vagus to the eleventh nerve of higher vertebrates, 

 and considers that it is partly general cutaneous in Necturus. 

 Druner considers that the root is related to the trapezius mus- 

 cle, but does not trace it through the ganglia in the Urodela 

 which he investigated (Salamandra, Triton, Menobranchus and 

 Proteus). In Amblystoma, however, the manner of origin and 

 the distribution of the nerve afford strong evidence that it is to 

 be considered as the true representative of the n. accessorius. 



In his work upon Urodela Driner treats the lateralis and 

 glossopharyngeal roots as a single root, but recognizes the func- 

 tional value of the two parts. His observations, on the whole, 

 indicate that the relations of the roots of this complex in the 

 Urodela he studied agree in all essential features with those of 

 Amblystoma. 



Kingsbury has given a detailed account of the smaller 

 divisions of these roots as they emerge from the brain in Nec- 

 turus. The variation, however, either developmental or indi- 

 vidual, is so great in Amblystoma that little emphasis can at 

 present be placed upon any particular arrangement of these 

 minor rootlets of the ninth and tenth nerves. They have no 



