A PECULIAR STRUCTURE IN THE ELECTROPLAX OF 
THE STARGAZER, ASTROSCOPUS GUTTATUS 
JAMES G. HUGHES, JR. 
From the Histological Laboratory of Princeton University, U. S. A. 
THREE FIGURES 
The purpose of this paper is to determine the function and 
composition of the peculiar pointed fibers and long pointed rods 
lying in the electric layer of the electroplaxes of the stargazer, 
Astroscopus guttatus. 
Before proceeding with a discussion of these rods, a_ brief 
description of the electric organ of this fish (according to Dahl- 
eren)! will be given. 
The electric apparatus is composed of two organs, which 
form two vertical columns roughly oval in horizontal section, 
and placed behind and somewhat under each eye. Each organ 
extends from the peculiar bare spot on the top of the head 
down to the tissues which form the roof of the oval cavity; 
and is composed of about 200 thin layers of electric tissue, 
which extend horizontally all the way across the organ. These 
layers of tissue are flat, and always at the same distance from 
one another. Each layer contains about 20 electroplaxes, the 
outlines of which present a very irregular or scalloped appear- 
ance. The electric tissue in which the electroplaxes are im- 
bedded is in appearance a Jjelly-like or mucous-like tissue, usu- 
ally known as electric connective tissue, and which I have shown 
in the course of my work to be of the same composition as white 
fibrous connective tissue. The nerve and blood supply runs 
in the above tissue. The general form of a vertical section 
of an electroplax is shown by figure 1, which is a drawing of 
part of a section of a single electroplax. 
Each electroplax is composed of three principal layers, a 
nervous or electric layer which forms the upper surface, a 
1 Anat. Anz., Bd. 29, S. 387, 1906. 
97 
