MORPHOLOGICAL STUDIES. 
217 
the lateral horn and pass out with the other motor nerves in 
the anterior root ; and the sensory visceral fibres take their 
origin in Clark’s column and pass out with the posterior root. 
Both sets of sensory fibres possess ganglia, the motor fibres 
being unganglionated. 
I do not propose to devote any great amount of space to the 
examination of the bearings of Dr. Gaskell’s results on the 
cranial nerves as given by himself, or as they appear to me ; 
still, a few morphological conclusions can be drawn from those 
researches just as my results may be of use to the physiologist. 
The oculomotorius, trochlearis and abducens correspond mor- 
phologically and physiologically, as van Wiihe (No. Gl), Hill 
(2G), Gaskell (19), 1 and His (34) have insisted, to the motor 
somatic roots of spinal nerves. They arise in the combination 
of the anterior horn in the head, and they are distributed to 
muscles of the somatic system. Thus one is faced at once by 
the conclusion that the motor visceral fibres do not enter 
anterior roots in the head, and, on the contrary, they pass 
through the posterior roots, which are mainly sensory. 
Now, these motor somatic fibres in the trunk develop as 
direct outgrowths of the spinal cord, and as the ganglia which 
form them lie in the cord they ought also to arise in the head 
as direct outgrowths of cells in the brain, and in the homo- 
logies of anterior root of spiual nerves. The latter is certainly 
not the case, for they pass out with the posterior roots : and 
the question arises. How do they develop in the head ? Either 
the old course with anterior roots in the head never existed, 
or it has been lost, and they have acquired new paths through 
the afferent fibres of the posterior root. 
Which of these things is really the case I cannot decide, for 
as yet I have been unable to prove the first by the demon- 
stration of an element of the posterior root of a cranial nerve 
which develops as a direct outgrowth of cells from the brain. 
1 Gaskell lias quite recently arrived at very different conclusions (‘Proc. Roy. 
Soc.,’ Feb. 9th, 1888), which appear to be largely erroneous. I shall consider 
them in the second part of this work, after Dr. Gaskell has published the com. 
plete paper. 
