6 Cincinnati Society of Natural History. 
hood of the nucleus is composed of peculiarly arranged 
fibrils, forming a “‘spiral”’ or ‘“‘swirl.”” These appearances 
are caused by the fibrils, which take very irregular courses 
and partially encircle the nucleus in a tortuous manner. 
III. FINER STRUCTURE OF THE GROUND SUBSTANCE 
OF THE SPINAL GANGLION CELLS IN THE 
ADULT WHITE RAT. 
It remains to discuss the real nature of the fibrillar struc- 
tures mentioned above, and to this end the structure of the 
ground substance of the nerve-cells must first be considered. 
Concerning the structure of the ground substance in nerve- 
cells, two main views are held: the “fibrillar” and “ non- 
fibrillar”? structure. The former theory may also be sub- 
divided. One view is represented by the theory of Bethe (*) 
who regards.the ground substance as composed of “ Peri 
Fibrillar Substanz’’ and ‘‘Fibrillen.”? The so-called Fibrillen 
are independent individuals distributed throughout the cell- 
body in a certain way, where they neither anastomose nor 
branch. Another fibrillar theory is that of Apathy (’). 
According to this author, the primitive neurofibrils are to be 
distinguished by means of special technique, in the nerve- 
cells as Bethe describes. These fibrils however, are not 
isolated, but are connected with each other by means of deli- 
cate branches, thus forming a very complicated anastomosis 
within the nerve-cells. 
The non-fibrillar theories may also be divided into two 
groups, represented by the theory of Apathy ('), Nansen 
(7), Biitschli (*), etc. Nansen holds the view of primitive 
tubular structure of the formation of the ground substance 
of the nerve-cells, that is, the ground substance is entirely 
composed of extremely small tubules which are directly 
continuous with the neuraxone. 
*) Bethe, A.—Uber die Primitiy Fibrillen in den Ganglien-zellen von Menschen 
und Wirbelthieren.— Arch. ftir Mikrosk. Anat., Bd. 51. 
(1) Apathy.— Das leitende Element des Nervensystems, u. s. w.— Mitheil. d. 
Zoolog. Station zu Neapel, B’d NII, ’97. 
(2) Nansen, F.—The structure and combination of the histological elements of 
the central nervous system.— Bergen, ’87. 
(3) Butschli.—Investigations on microscopic forms and on protoplasm.—’g4. 
Translation to English. 
6 
