397 
The nerve-supply of the electroplax seems, in my preparations, 
to be not essentially different from that of Raja and of Tetronarce. 
It consists of a number of medullated fibres that run between the 
layers in the electric connective tissue. They were seen to lose the 
medullary sheathes and, dividing into many fine fibrils, to end at 
every point of the electric surface probably in endplates as in Raja. 
It was not decided that these endplates did not have any peculiar 
relation to the rod-like structures. 
The second layer (Fig. 5 etc., 10) of the cytoplasm of the elec- 
troplax was not apparent in all of the electroplaxes that came under 
observation and did not seem to be a very importent differentiation. 
In it the cytoplasm showed a web-like structure the meshes of which 
were longer in the horizontal direction than in the vertical’ This 
layer was narrow and stained much lighter than the cytoplasm on 
either side of it. It contained no nuclei although the nuclei of the 
lower layer sometimes were placed very near to it and in an exami- 
nation of more material some will probably be found there. | 
The third and lower layer (Fig. 5 etc., 77) is that which is con- 
tained in the papillae and the surface from which they arise. It is 
a rather dense and homogeneous cytoplasm containing a good supply 
of nuclei which are distributed evenly through its substance. The 
nuclei are all the same in appearence, oval and slightly different from 
the electric nuclei in their distribution of chromatin. 
The important feature of this layer, which it shares in common 
with the other two layers is the striation which appeares in this tissue 
in a more distinctive form than in any other electric fish not excep- 
ting Raja or Mormyrus. ‘This striation (Fig. 5 and 9, 78) consists, 
in sectional view, of fine sharp lines most accurately spaced and most 
Strictly parallel. Like the corresponding striations in Raja the lines 
are not straight but much curved in many directions. Under these 
circumstances the lines could not be continuous and parallel at the 
Same time throughout the section and so we find them set apart into 
groups that seem to have no relation whatever with one another. 
Arguing from what I know to be the case in the electric tissue of 
Raja I feel perfectly confident in asserting that the lines of this 
Striation represent the edges of an equal number of curved and parallel 
surfaces seen in actual or in optical section. The distance between 
the lines varies so little however that one is puzzled to understand 
what has become of the oblique and surface views of the striation. 
It is probable that such pictures are obscured or hidden by a super- 
imposed optical view of a transverse section. The width of the stria- 
tion is about 0,6 u. 
