ELECTRICAL FISHES 



377 



numerous (" secondary ") transverse partitions, set vertically to the 

 long axis, into single, flat, quadrilateral chambers or compartments, 

 lying one behind the other, and enclosing the true electromotive 

 elements of the " plates " (Kolliker's " spongy bodies "). It appears 

 from even superficial consideration of a long section that the 

 single longitudinal columns of the electrical organ have in some 

 degree replaced the involuted, cone-shaped muscle-segments, so 

 that the primary septa are in part only a restoration of the 

 tendinous partition walls of the sacro-lumbar muscles, and, like 



MM 11 :,, ii it iiii 



Mi 



sill 



FIG. 245. Raja clavata : L.S. of electrical organ in the,, tail, a, Anterior end, lying between the 

 layers of M. sacrolumbalis (magnified three times) ; b, from the centre of the organ ; the electrical 

 plate lies at the anterior wall of each compartment. (M. Schultze.) 



these, form cones with pointed anterior ends, fitting parallel into 

 one another (Fig. 245). Fig. 247 gives a good representation of 

 the arrangement of the single compartments within the columns, 

 as well as the position of their contents. 



These figures show that the comparatively thick plates, which 

 are irregularly bounded on the posterior side, are attached to the 

 anterior wall of each compartment, and occupy about one- third 

 of the available inner space. Under a higher power the plates 

 are seen (Fig. 248) to be surrounded by gelatinous connective 

 tissue, which fixes them within the cavity of the compartment. 

 The nerves to each compartment travel, as Kolliker (16) showed, 

 from the anterior wall to the anterior plane, or goblet-shaped 

 surface of the plate, forming by rapid division a rich plexus of 

 non-medullated fibres. The true mode of ending is of course 



