— 68 — 
3) ,,Protoplasmafortsåtøe" which produce the combination of the 
ganglion cells with each other. They have the same appearance as 
the cell protoplasm. 
The »Stammfortsåtze« are rare and only occur in unipolar cells. 
The »Protoplasmafortsatze« occur in bipolar and multipolar cells as 
well as also in the smallest unipolar ones, which should, conse- 
quently, completely want »Mark«- or »Stammfortsatze«. 
In his description of the »Markfortsatze« he expresses himselt 
somewhat indistinctly. »Markfortsatze«, he says p. 416, occur in all 
cells, besides those which have a »Stammfortsatz«, and this he says 
after having just described cells wanting »Mark«- as well as »Stamm- 
fortsåtze«. At one point he says: »Die geminipolen Zellen (conse- 
quently bipolar cells) haben nur Markfortsatze«. Immediately after- 
wards he says : »Keine Zelle hat zwei Markfortsatze, sondern immer 
nur einen« (1. c. p. 416). How this is to be understood is not, I 
think, very easy to say. 
Immediately afterwards he says, again, that »die oppositipolen 
Zellen (consequently bipolar cells) sind diejenigen Gebilde, welche 
noch am ehesten als solche betrachtet werden konnen, welche zwei 
Markforsatze haben. He is, however, disposed to »auch bei Everte- 
braten wie bei Vertebraten (cmfr. his previous paper 1883 Arch. f. 
mikr. Anat. XXI) die oppositipolen Zellen als Nervenzellen sensu 
strictiori nicht anzuerkennen, sondern sie nur als kern- und proto- 
plasmahaltigen Interpolationen der Nervenfortsåtze resp. -fasern zu 
erklaren.« A view in which perhaps I, to a certain extent, can agree 
with him; though I have only succeeded in finding extremely few 
similar cells or formations. 
Rawitz describes, in the Acephales, an arrangement of the cells 
somewhat similar to what I, on previous occasions, have mentioned in 
Ascidians etc. In the outer layer, unipolar cells exclusively occur, in 
the middle layer, all kinds of cells, unipolar, bipolar and multipolar ones, 
and in the inner layer, close to the »dotted substance« multipolar 
cells principally occur. This is, as I have previously declared, in 
the closest relation to what I call the nutritive function of the 
protoplasmic processes, and it has not, in my opinion, the significance 
which Rawitz ascribes to it. 
»Der Markfortsatz oder Hauptfortsatz der multipolaren Ganglien- 
zellen «, of the Acephales are, according to Rawitz, »das Homologon 
des Deiters'shen Fortsatze der polyklonen Ganglienzellen im Vorder- 
horn des Riickenmarkes der Vertebraten. « And he believes it to 
be »morphologisch durchaus nebensåchlich, ob, wie bei dem Axen- 
