98 
IOWA ACADEMY OF SCIENCES. 
THE VAGUS AND ANTERIOR SPINAL NERVES IN 
AMPHIUMA. 
BY H. W. NORRIS. 
After the recent excellent description of the cranial 
nerves in Amphiuma by Kingsley* it may seem hardly 
worth while to present any further account. But having 
the good fortune to possess some material in which the 
individual nerve trunks can be traced with great dis- 
tinctness through the various plexuses the writer ventures 
to present the following brief account of the interrelation- 
ships of the vagus and anterior spinal nerves. The points 
wherein this paper is at variance with that of Kingsley are 
probably in most respects of not great importance, and 
possibly due to differences in the state of development of 
the specimens examined. This account is based on the 
structures studied in a specimen of 130 mm. in length. 
From the glossopharyngeal-vagus ganglion 1 find eight 
nerves given off. The first and anterior of them, Jacob- 
son’s commissure (1) , divides as it leaves the ganglion into 
two branches, one the commissure proper passing antero- 
ventrally around the ear capsule to unite with the 
hyomandibular branch of the seventh cranial nerve, the 
other a dorso-laterally directed branch that unites with a 
second vagus trunk {2) at the lateral ventral border of the 
longissimus dorsi muscle. This off-shoot from Jacobson’s 
commissure is probably the nerve described by Kingsley 
as given off from the first branchial nerve and passing to 
the digastric muscle. After its union with the small 
second vagus trunk the main ‘part of the nerve runs 
anteriorly between the longissimus dorsi and anterior 
digastric muscles. It evidently supplies lateral line sense- 
* Kingsley, J. S. — The Cranial Nerves of Amphiuma. Tuft’s College Studies, No. 7, 
1902. 
