677 
neurone and its parts leave, indeed, hardly any room for doubt of 
the perfectly mechanical character of its arrangement. Though it is 
not possible to demonstrate this in details, because it is not yet 
fully known what takes place in the nerve fiber during the trans- 
mission of the stimulation process, the impulsions, from and to the 
ganglion cell, yet our present view of the nature of this mechanism 
ean be tested by what we know about this arrangement. 
What is transmitted in the nerve fiber as impulsions is, beyond 
doubt, a process of dissimilation, and it is highly probable that the 
colloids, contained in the living substance, play an important rôle. 
The plasm of the ganglion cell and the axone possess ‘“Spumoid- 
struktur’ (Rhumbler), is an emulsive foam mixture, consisting of two 
liquid phases. The denser of these colloid substances forms the walls 
of the minute spumoid compartments (“Schaumkämmerchen” of 
Rhumbler); so semipermeable membranes or osmotic films can act 
selectively on the ions liberated by the disaggregation of the mole- 
cules. Thus the anions diffuse in centrifugal or centripetal direction 
from one spumoid minute compartment to another *). 
Material particles move in any case from one end of the nerve 
fiber to the other. Not the same particles: the movement is trans- 
mitted from one spumoid compartment to another lying in front of 
it, as it were from one transverse layer to another, but the work 
performed thus must be equal to that of a transverse layer of equal 
mass which moved from one end of the nerve fiber to the other. 
But the process of stimulation is not transmitted in this way from 
one end to the other in the whole nerve fiber; this takes only place 
in the axone. We see the axone taking its central origin or termi- 
nating centrally iz the plasm of the neurocyte, with gradual transi- 
tion; it is enveloped with myeline only at some distance from this ; 
the medullary sheath terminates at the muscle fiber, and the motor 
nerve end-plate is but a plate-like or antler-like extension of the 
axone. It also appears that at the peripheral ends of the afferent 
nerve fibers the axone is the real conductor. Though the medullary 
1) Cf: W. Neanst, Zur Theorie der elektrischen Reizung. Nachrichten von 
der Kön. Gesellschaft der Wissenschaften zu Göttingen. (Mathem.-physik. Klasse). 
1599, p. 104—108. — Max Verworn, Allgemeine Physiologie. Sechste Auflage. 
Jena 1915, p. 134 et seq., 319 ete. — O. Bürscuur, Untersuchungen über mikros- 
kopische Schéiume und das Protoplasma. Leipzig 1592. Hans Heup, Beiträge 
zur Struktur der Nervenzellen und ihrer Wovrtsätze. (Zweite Abhandlung). Archiv 
fir Anatomie und Entwickelungsgeschichte. Leipzig 1897, p. 204—289. — L. 
tnumeten, Das Protoplasma als pliysikalisches System. Ergebnisse der Physiologie. 
(Asner und Spino). Jalirgang XIV. Wiesbaden 1914, p. 484—617. 
