22 F. L. LANDACRE 
2. THE NERVUS OLFACTORIUS AND NERVUS TERMINALIS 
The connection between the olfactory pit and forebrain, 
which has no olfactory bulb at this time, consists of a thick 
cellular and fibrous mass which probably represents both the 
above mentioned nerves. The main portion of this connection, 
that lying more dorsal in position in the plot (fig. 1, n.olf.), 
consists of a dense mass of medium sized cells extending from 
the brain wall back to the epithelium of the olfactory capsule, 
where, just before coming into contact with the brain, it breaks 
up into three or four masses of cells where it is connected with 
the brain. The anterior end of this mass is solid and does not 
show the loose character of the posterior end. There are iso- 
lated strands of fibers in this mass aside from those mentioned 
below but their connec‘ion with neither the brain wall nor the 
olfactory epithelium could be made out with certainty. These 
strands of fibers are identified as olfactory fibers. 
In addition to the main dorsal portion described above, there 
are two strands of cells on the anterior end of the nerve lying 
ventral 1o the main strand containing definite fiber bundles 
(fig. 1, N.Ter.). The entrance of these fibers into the brain 
wall at a point more ventral and median than the main mass of 
cells is easily made out and the fiber bundles can also be traced 
through the connecting cellular mass to the olfactory epithe- 
lum. These two strands in the specimen plotted are repre- 
sented by only one strand in four other specimens of about the 
same age and there is only one strand of cells and fibers on the 
opposite side of the same specimen. Both strands are accom- 
panied by a limited number of round cells lying in the position 
indicated by Locy (’99, ’05) as the location of the ganglion of the 
nervus terminalis, namely near its entrance into the brain wall. 
In the 30 mm. embryo the ganglion of the n. terminalis while 
small is well defined and well isolated. There can be no doubt 
as to the identification of these as the nervus terminalis on 
account of the point of entrance into the brain wall and the 
greater degree of development. lLocy (’99, ’05) gives a rather 
full account of the history of this nerve, but his account shows 
