240 Papers from the Department of Marine Biology. 
the axone leaving from the ventral surface. So that it may be stated 
that in cases of orientation the plasmosome is not oriented toward the 
axone or in the structural (physiological?) axis of the cell, but that it 
is always oriented in the dorso-ventral axis of the cell. Of course, the 
dorso-ventral axis might be a physiological axis, but its independence 
of the structural axis as formed by a line drawn through the majority 
of the dendrites, the nucleus, and the axone, would still require an 
explanation of why it was dorso-ventral. It could only exist in this 
direction to accommodate the factors of gravity or the electric current, 
and we shall see that in T'orpedo it does not do this. It thus seems to 
the writer that the orientation, where found, is a more or less perma- 
nent condition, persisting over a considerable period of the animal’s life. 
Fic. 5.—Diagram of form of electric lobes as seen in transverse section, with several 
enlarged outlines of a few cells on right that show how the neurite may arise 
from any surface of the cell and how the orientation of the plasmosome is 
always independent of this factor. Nuclei alone shown on left. 
The fifth hypothesis, that this more or less permanent orientation 
is of value to the physiological activities of the cell, is a difficult one to 
discuss. Since it appears to be much more profitable to consider it in 
a paper on the more highly differentiated electric nerve-cell of Tetro- 
narce occidentalis that is shortly to appear, it will be dismissed here with 
the remark that no strong evidence has been produced to show that 
such relation exists. Against it appear several facts: 
First, the condition mentioned above, that the axis of orientation 
of the plasmosome does not correspond in all cases to the functional 
axis of the cell, would seem to indicate this. It might be assumed that 
any physiological action taking place in a definite direction would 
