. Carnegie Institution of Washington publication. Structure and Polarity of Electric Motor Nerve-Cell in Torpedoes. 217 Each of the cells in question is a typical nerve-cell of extraordinary size. They grow with the growth of the fish to a certain degree and in a well-developed fish, of say 35 cm. in length, these cells will average 75 microns in diameter. They are compact in shape, as the various figures will show, and each gives off from 20 to 40 processes, one of which is the neuraxon or main impulse-carrier from the cell to the electro- plax which it supplies. The remainder are dendritic i
. Carnegie Institution of Washington publication. Structure and Polarity of Electric Motor Nerve-Cell in Torpedoes. 217 Each of the cells in question is a typical nerve-cell of extraordinary size. They grow with the growth of the fish to a certain degree and in a well-developed fish, of say 35 cm. in length, these cells will average 75 microns in diameter. They are compact in shape, as the various figures will show, and each gives off from 20 to 40 processes, one of which is the neuraxon or main impulse-carrier from the cell to the electro- plax which it supplies. The remainder are dendritic in structure and are thin and richly branching. Some traces of a weak polarity in the arrangement of the processes can be seen (plate 3, all figs.) in the fact that in many of the cells the neuraxon is given off at one end of a slightly elongated cell, while a majority of the dendrites are given off at the other end. In other cases this is not so apparent and the distribution of the dendrites seems to be very general and not restricted Ill' It \ { I \ \ \ \v \ \ \ v-- \ x "-- \ "- —- "s \ \ •J)}} / FIG. 1. FIG. 1.—Diagram, after Cavendish, to indicate course taken through the surrounding water by the electric current generated at time of discharge of electric organ in Torpedo marmorata. Copied from "The Physiology of Nerve, Muscle and Electric Organ" by Dubois- Reymond, translated by J. Burdon-Sanderson. Oxford, 1887. FIG. 2.—Improved and corrected diagram of same conditions as in fig. 1, by Dubois-Reymond. Copied from same source as fig. 1. to any one area. Preparations made by teasing bits of electric lobe that have been macerated for 24 to 36 hours in one-third alcohol serve to show these features to advantage in plate 3, and in such isolated cells the processes can be seen for some distance, being seldom broken off less than the diameter of the cell in length, while in many cases they are shown for a much greater distance. There is seldom
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