THE SKIN END-ORGANS OF THE TRIGEMINUS AND 
LATERALIS NERVES OF BDELLOSTOMA DOMBEYI. 
BY 
HOWARD AYERS anp JULIA WORTHINGTON. 
WitH 10 FIGuREs. 
Owing to the noteworthy and rather complicated internal relationship 
of the Trigemius and Acustico-Lateralis nerves of Bdellostoma, it has 
seemed best to publish a brief abstract of the results which a study of the 
peripheral terminations of these nerves has produced. The material on 
which the study is based consists of preparations made by the Golgi, the 
methylene blue, and the gold chloride methods, as well as sections stained 
with various coal-tar colors. 
Stated briefly, the distribution of these nerves in the head of Bdellos- 
toma is as follows: the skin territories of the dorsal part of the head 
cephalad of the brain, of the four tentacles, of the rim of the nasal tube, 
and of the upper part of the lip, are innervated by the trigeminus. The 
dorsal skin over the fore part of the brain and a little laterad of it is 
innervated by the Jateralis posterior. The skin at the side of the head in 
front of the brain is within the territory belonging to both sets of nerves. 
Both trigeminus and lateralis fibers run to it through a common trunk, 
the lateralis component of which is the lateralis anterior. 
The sense organs of the ¢rigeminus described in this paper are those 
occurring in the tentacles and the rim of the nasal tube, while the sense 
organs of the lateralis are those found in the lateral line canals. Both 
kinds have been compared with those found in the territory supplied by 
both nerves. In this way we have sought to obtain-a clear discrimination 
of the two kinds of organs. 
The skin of Bdellostoma consists of two primary layers, a dermis and 
an epidermis. Essential agreement in structure with the skin of 
Petromyzon is the noteworthy fact. 
The epidermis, when studied in sections stained with the usual general 
stains, such as hematoxylin or carmine, is seen to be composed of an 
AMERICAN JOURNAL OF ANATOMY.—VOL. VII. 
