201 
‚The simple macro-nerves of figs. 4 and 5 may now have become 
more complex owing to the development of additional fibrils. Details 
in the histogenesis of such nerves must be left over; suffice it to say 
that they not only conform to the mode of nerve-formation given in 
the succeeding paper, but that their study has helped to no little 
extent in rendering possible my results on the general histogenesis of 
nerve. 
In such nerves as those seen in figs. 7 and 8, especially when 
their development is studied from a complete series of Raja pre- 
Fig. 7. Transverse section 
of a R. batis of 43 mm. 
parations, the nature of the nuclei along the course of the nerve 
cannot be for a moment doubtful. In fig. 7 we have a large ganglion 
cell!) (w. gl. c.) intercalated in the course of a fibril. Instances of 
such are, as we have seen, not rare, and, indeed, all stages between 
ganglion cells as big or bigger than the one in fig. 7 and nuclei (nerve- 
forming nuclei) such as are shown in the same figure (n. n.) may be 
encountered. The ganglion cells on a nerve may then be small or 
big; if they cease to attain a certain size we can no longer regard 
them as specifically ganglionic, and, their energies being devoted to 
other purposes, they then become nerve-forming nuclei, or, if one will, 
nerve-forming cells. 
The reader may be asked not to suppose that free play is here given 
to the imagination. It is hardly a question of fancy at all; for in 
1) In later stages, like this one, groups of macro-ganglion cells may 
be often met with in the mesoblast. In such cases they would appear 
to be always provided with capsule cells, Such instances possess con- 
siderable interest in reference to the question of the relation of capsule 
cells to nerve-forming cells, for there is a gradual transition, as noted 
by Dourn in the spinal ganglia, between the two. 
