272 THE GYMNOTUS. 



the back there are two rows of glandular apertures, 

 through which a mucous fluid is discharged, for lubri- 

 cating the skin. There are two electric organs upon 

 each side of the gymnotus, a large one near the back 

 and immediately under the skin, and a small one nearer 

 the fin, and beneath the muscular texture by which that 

 is moved. There is also a portion of muscle between 

 the small organ and the large one. Both these organs 

 extend nearly to the extremity of the tail, becoming 

 thinner as that is approached ; and they occupy about 

 one half of the mass where they are placed, or more 

 than a third of the whole fish. 



The structure of these organs has a considerable re- 

 semblance to that of those of the torpedo. They are 

 divided lengthways into tubes or pillars ; and then 

 again into cells by transverse partitions. The parti- 

 tions are very near each other, there being about two 

 hundred and forty in an inch. The longitudinal ones, 

 which are at the greatest distance in the largest speci- 

 mens, are much further apart, some of them being half 

 an inch or even more. The longitudinal divisions of 

 the small organs are closer, and they lie in curves, but 

 the form of their organization is the same. Thus, while, in 

 their internal structure, the organs of the gymnotus are 

 like those of the torpedo, they seem to consist of the 

 same materials, albumen and gelatine being the pre- 

 vailing substances in both. The superior power of the 

 gymnotus may depend partly on the larger size of its 

 organs, and partly upon the larger surfaces of the trans- 

 verse cells ; at least that would be the case if they were 

 batteries of electric jars, which they resemble in some of 

 their phenomena, though, as is the case with the other 



