Structure and Polarity of Electric Motor Nerve-Cell in Torpedoes. 245 



a condition that would have to obtain if its orientation in nature were 

 clue to the natural electric current. It does, however, move part way 

 there, as far as the dissolved chromatin mass extends. When one 

 remembers that this chromatin mass extends throughout the nucleus 

 under normal conditions, it seems possible that the electric current, 

 when in proper strength, may tend to move the plasmosome in the 

 kathodal direction, which is the direction of the orientation that we 

 are discussing. This possibility, however, is not a strong one. 



Having considered the results of strong electric currents, I will now 

 compare with them some results obtained by what I shall call very 

 strong currents, such as were used in experiments on torpedoes Nos. 

 5 and 4. 



Figure 20, plate 4, from torpedo No. 5, will show these results satis- 

 factorily, and it may be best studied by a simple comparison with the 

 last figure (19, plate 4), which represents the effects of strong currents. 

 The same strong trend of the nucleus toward the kathode with the 

 resultant semilunar space on the anodal side of it is apparent. Also, 

 the movement of the principal chromatic material in a homogeneous 

 mass toward the anode. The same little "blister," probably containing 

 a soluble constituent of the nuclear content that has been passed 

 through the anodal surface of the nucleus, is to be seen and is even 

 larger and better developed than with the strong current. 



This specimen, being stained with iron hematoxylin, shows the 

 kathodal collection of chromatic material which, as has already been 

 stated, is particularly susceptible to this stain. It may also be noted 

 that the neurosomes are shown by the fixation and stain and that a 

 series of light-staining, elongate areas are to be seen in the cytoplasm. 



Two marked differences are seen as a result of increased electric 

 action: the anodal aggregation of chromatic material has been differ- 

 entiated into a thinner, lighter-staining kathodal layer, and a main 

 anodal body that contains the plasmosome and the regularly spaced 

 karyosomes. These latter show the second marked difference. Each 

 begins to swell up and acquire a vesicle-like form with a non-staining 

 interior. This bubble-like swelling does not begin from the center, but 

 from near one side of each karyosome, so that the resulting spherical 

 shell has a lump on one side which represents the original mass. The 

 writer has no explanation for this reaction. 



Again, we find that our main point to be deducted from the examina- 

 tion of these very strong electric-current experiments is that the plas- 

 mosome is not moved all of the way toward the kathodal end of the 

 nucleus, but that it is moved to the kathodal limit of the anodally 

 segregated chromatin. 



It having been concluded that the electric current was not a direct 

 cause of the orientation, the question of gravity was taken up for con- 

 sideration. As in the case of electricity, this force was applied to the 



