382 



ELECTRO-PHYSIOLOGY 



long, narrow, still plainly striated stalk to the plate-rudiment, 

 which has meantime increased considerably in breadth owing to 

 proliferation of nuclei. Its ventral half consists of an almost 

 transparent plasma traversed by little fibres (muscle-fibrils ?), 

 while the characteristic rounded nuclei lie in a finely granulated 

 dorsal stratum (Babuchin, Fig. 249, e). An isolated column at 

 this stage consists of thick loaf-shaped bodies, not perfectly regular, 

 and separated by embryonic cells. These do not take up the entire 

 width of the column, but lie near and over each other." The 

 stalks (remains of primitive muscle-fibres) are often attached 

 laterally to the plate-rudiment, and become steadily thinner, 



subsequently disappearing altogether, 

 while the latter now finally assume the 

 shape of very thin plates, and fill up the 

 entire cross - section of the column. 

 Isolation of the plates is very difficult at 

 this stage, seeing that the external border 

 cells gradually coalesce into a firm sheath 

 of connective tissue round the electrical 

 prisms. Little as the structure of a 

 complete column of Torpedo recalls a 

 striated muscle structure, there cannot, in 

 view of the above facts, be the slightest 

 doubt as to the genetic relations between 

 the two tissues, and one of the most 

 significant advances, not merely in the 



FIG. 250. L.S. of embryonic column . , . ,, , . , ,, 



of Torpedo, p = rudiment of anatomy, but also in the physiology oi 

 piate. (Babuchin.) ^Q electrical organ, was the discovery 



by Babuchin of this connection. As Engelmann remarks (8, p. 

 149), "Nowhere else in nature have we, side by side, and so 

 completely accessible to research, the anatomical and physiological 

 factors for the vital production of mechanical and electrical 

 energy." 



Unfortunately all attempts made by C. Sachs to determine 

 the embryonic development of the organ of Gymnotus were 

 fruitless, and we can only conjecture that it occurs in the same 

 way, generally speaking, as in Torpedo. 



In the Kay, on the other hand, there is no doubt as to the 

 very interesting development of the less highly differentiated 

 pseudo-electric organs. 



