ELECTRIC ORGANS 



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while the rest of the fibre fails to grow. The structure becomes 

 toadstool-shaped, with the nerve arborizing on the seat of the 

 stool. The front aspect of the disc, therefore, corresponds 

 to a nerve-ending in a muscle. Its middle layer indicates 

 clearly that the fibre makes an abortive attempt to develop 



FIG. 18. ELECTRIC ORGAN OP A SKATE IN LONGITUDINAL SECTION A, SLIGHTLY, B, HIGHLY 



MAGNIFIED. 



A shows the compartments into which septa of fibrous tissue divide the organ. In the centre 

 of each compartment is a disc formed from a modified muscle-fibre. Nerves ramify in 

 abundance on its anterior surface. B, a minute portion of a disc. At the top are seen 

 nerve-fibres in delicate nucleated sheaths ; then follow the nucleated layer with which 

 they come in contact, the contorted laminae which represent the striations of the muscle- 

 fibre, the granular nucleated substance of its posterior layer, some connective tissue, 

 a capillary bloodvessel containing oval nucleated corpuscles. In a tissue space, a single 

 coarsely granular leucocyte is to be seen. 



cross-striation. It is laminated, the laminae strangely con- 

 torted ; in section they appear, not as plain lines, but as rows 

 of dots, evidently a suggestion of longitudinal stria tion. The 

 posterior layer of the disc consists of granular protoplasm 

 drawn out as a number of short backwardly directed tongues, 



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