Structure and Polarity of Electric Motor Nerve-Cell in Torpedoes. 219 
found to be lacking in the extreme periphery of this and other nerve- 
cells, where its absence has been accounted for in various ways by 
Rhode (30) and other writers. As this substance is also of no signifi- 
cance in regard to any polarity or orientation of the cell, it will not 
be dealt with further in regard to its properties or meaning and its 
literature will not be cited. It may be seen in a well-stained condition 
in figure 1, plate 1. 
Another content of the cell was of more importance as a guide to 
polarity. This consisted of a number of granules of a substance first 
described by M. Shultze and subsequently more definitely by Garten 
(17 8). These granules were best studied by the writer in the living 
cell and then in macerated and teased specimens and lastly in sections. 
Their most prominent feature is only shown when studied in the living 
cell. Here they show a very high index of refraction, which disappears 
when treated with the usual clearing reagents. Thus these granules 
do not appear in unstained sections on account of their refractive 
properties. As Garten says: “am ungefairbten Preparat waren die 
Kornchen nicht sichtbar.”’ 
In fresh or recently fixed formalin material these granules were visible 
not only by reason of their refraction quality but also because of their 
color. This was much more noticeable in some cases than in others 
and in one case their color was a rich, golden-orange, like some of the 
lighter brown pigments found in vertebrate skin and elsewhere. The 
depth of color in the granules was found to correspond to the external 
and internal color of the electric lobes of the brain in which they are 
found and in Torpedo ocellata and Torpedo marmorata this varied from 
a faint yellowish tinge in fully 50 per cent of the specimens to the rich 
orange found in one or two examples as mentioned above. It thus 
would seem that in certain specimens this substance gives the lobes 
their peculiar color, but that whether colored or not the same granules 
exist in all specimens. The electric lobes of the large American 
torpedo, T'etronarce occidentalis, are but little different from the rest 
of the brain in color and it will probably be found that in this form the 
refractive granules are present but colorless. In Narcine braziliensis, 
the little torpedo of South America and the West Indies, the electric 
lobes are a very deep and brilliant orange in color, caused undoubtedly 
by the coloration of these same granular structures in all specimens. 
In size these granules were variable and usually less than a micro- 
millimeter in diameter. Some might have attained to this size. 
Garten speaks of them as round, but in the fresh cells many of them 
seemed irregular in shape and decidedly angular and elongate. In 
fixed and stained sections (plate 1, fig. 1) they appear round. 
The fixation and staining of these granules seems difficult, and best 
results were attained by a quick, hard fixation with pure sublimate or 
Bouin’s fluid and a rapid embedding. Figure 1 of plate 1 shows a case 
