l88 Papers from the Marin Biological Laboratory at Tortugas. 



In doing this it has formed a luch more intimate connection than may 

 be seen in other places where te nerve-fibers touch the electroplax very 

 closely, even being partly embcded in it. or running through the fundus 

 that lies between two papillae, here the fiber is closely pressetl on thrte 

 sides by the surface of the ele<roplax. In these fiber contacts the con- 

 nective-tissue sheath persists, wile in the club-shaped or heavily rounded 

 endings the connective-tissue seath is lost, lefc at the surface, and the 

 lit lie protoplasmic bridges, shoii when slight shrinkage has taken place, 

 testify to the intimacy of the c( tact. In addition a slight amount of fine, 

 golden-colored granules surrouiis the nerve-ending, lying on its surface, 

 between it and the substance < the electroplax (figs. 24 and 25, plate 9). 

 These granules are not found <>i my other part of the nerve surface. 



Naturally the pa[>er of Schchter (30) was carefully examined to see 

 what he had found as to the end g of the electric nerves on the related form, 

 Mormyrus oxyrhynchus. He hi adult material, but otherwise was no 

 better off than the writer in {2 F>ossession of material which had been 

 treate<l es(x^cially for neurologic study. He describes the nerve-fibers with 

 their medullary sheatiis as com 14 in contact with the large process of the 

 eleclropl.ix and then suddenly cling just as they reach certain large inden- 

 tations of the surface of this eltrophix. He fotinfl in these indentations 

 only .1 little coagulale<l materi.iimd some nuclei. 



Ihe writer has no doubt lat the slight coagulum represents what 

 remains of a club-shajx-il nervcnding similar to that which he finds in 

 Gymnarchus. The nuclei, frontheir [xjsition in Schlichter's picture, are 

 evidently the nuclei of termina connective-tissue coverings. If this idea 

 be correct we w ill have a very snple but interesting form of nerve-ending 

 much larger in size than that iund on any muscle or any other electri 

 organ and one in which it will I, apparently, easier to study the intimat 

 contact of nerve-substance witi motor-substance from a cytological poii 

 of view than in any other form. In particular, we should try to stain th 

 endings with the nitrate of silv( and methylene blue methods devised 

 neuro-cytological studies. Thi^work, however, can be undertaken - 

 on the ground, with good laboitory facilities and with an abundant 

 fresh material. 



The writer has published oservations on some peculiar horiz- 

 pointed rods, or pointed thread found imbedded in the electric Ia\ 

 the electroplax of Astroscopus. .t that time he suggested that they 

 be in some way homologous wit or related to the "Sg^y^n^be< 

 the absence of any other weldefined "Stabche^ 

 structures are not found in thoresent Gymnat 

 been seen and described in Raji in a paper 

 presence in Raja, in addition to le "Stabcht 

 different cell organs. 



One word in regard to certai possibil 

 of the electric organ in Gymncchus. 



^ 



