254 H. W. NORRIS 
NERVUS TERMINALIS 
Herrick (’09) has described the nervus terminalis of the frog, 
larval and adult, tracing it from its position in the olfactory 
nerve to the region of the anterior commissure. McKibben (’11) 
describes the same nerve in Necturus, Amblystoma tigrinum 
Diemyctylus torosus, Amphiuma, Acris, Hyla pickeringii, Rana 
catesbiana, and Bufo lentiginosus americanus, and finds its rela- 
tions quite like those described by Herrick in the frog. In 
Necturus, Diemyctylus, Amphiuma and Amblystoma he finds 
the nervus terminalis connected with the hypothalamus and the 
interpeduncular region. 
In Siren a tract of fibers may be traced from the base of the 
anterior series of rootlets of the olfactory nerve postero-ventrally 
between the olfactory glomeruli and the posterior root of the 
olfactory nerve to the ventro-lateral border of the olfactory lobe. 
Thence the tract passes caudo-medially, but soon enters the sub- 
stance of the brain wall, The nerve was traced posteriorly, 
ventral to and past the anterior commissure into the hypothal- 
amic region, and there was lost, but its direction seemed to be 
toward the ansulate commissure. The material studied was not 
favorable to the tracing of non-medullated fibers and in conse- 
quence the ultimate distribution of the fibers of the nervus term- 
inalis in the brain could not be determined. But in general, as 
far as traced, it showed a similarity to the corresponding tract 
in other Urodela, as described by McKibben.. Peripherally the 
nerve was not traced farther than the base of the olfactory nerve. 
That it enters the anterior series of rootlets of the olfactory nerve 
which innervates the posterior nasal epithelium seems almost 
certain. 
THE OPTIC AND EYE MUSCLE: NERVES 
Along with the rudimentary condition of the eye the optic 
nerve and the eye-muscle nerves have undergone a considerable 
degree of atrophy. All are present, however, and easily traced 
from external origin to distribution. Their distribution and 
arrangement seem to be the characteristic ones. No relations 
to ciliary ganglia were found. 
