oa Ss 
along with the nerve-forming cells sensu stricto from the anterior 
horn to the terminal region. 
These terminal cells must be regarded as ganglionic in character *). 
In connection with these chains of cells the formation of nerve 
takes place just as described in the case of the lateralis. 
About the oculomotor nerve and its allies, the trochlear and ab- 
ducens, the only statement to be made here is that the axis-cylinders 
and white substance are secretions of the chains of cells. Donen has 
devoted so much energy to the elucidation of the problems presented 
by these nerves, that in the existing stage of my work it would be 
folly to try and improve on his results. 
c) Histogenesis of spinal ganglia ete. 
The spinal ganglia and their nerves, as also the sympathetic, 
have come within the scope of my studies, and my results have much 
in common with those of Donrn. The amoeboid wandering of the 
young ganglion cells (and nerve-forming cells also), to which His has 
drawn special attention, is, as is well known very characteristic of 
the cells forming the above. 
There are the following main points to be noticed in the histo- 
genesis of spinal ganglia: 
a) Certain cells of the ganglionic foundation become arranged in 
chains to form the sensory nerve, the fibres being then secreted in the 
usual manner, and, in fact, becoming differentiated in the direction 
from the centre towards the periphery. 
b) As Donrn has described, I, too, have noted that it is from a 
group of cells which lie to the side of the developing nerve and which 
do not undergo this differentiation that a sympathetic ganglion arises. 
c) Again with Donrn, my observations teach me that all the cells 
in the ganglion do not become ganglionic; only the central ones have 
this destination, and they are early distinguishable by their lighter 
colouration with carmine. Other cells of the ganglion are used up in 
nerve formation. Still others form a capsule around each ganglion 
cell, and this is to me also a strong reason for holding a belief that 
the mesoderm plays no part whatever in nerve-formation ?). 
d) The central connection of spinal (or of the sensory portion of 
1) See the preceding paper, especially figs. 5 and 8, where the 
ganglionic nature of motorial end-plates is placed beyond doubt for a 
special case. 
2) In view of some statements in the preceding paper this might appear 
to be a contradiction in terms. The reader must, however, not overlook 
the circumstance that my position regarding the nature of the mesoderm 
is in sympathy with the views so ably advocated by KLEINENBERE. 
