ELECTRICAL GYMNOTE. 



55 



nothing more is necessary than to remove the skin, 

 which adheres to it by a loose cellular membrane. 

 But to expose to view the small organ, it is neces- 

 sary to remove the long row of small muscles which 

 move the fin. The structure of the organs is ex- 

 tremely simple and regular, consisting of two parts, 

 viz. flat partitions or septa, and cross divisions be- 

 tween them. The outer edge of these septa ap- 

 pears externally in parallel lines, nearly in the di- 

 rection of the longitudinal axis of the body. These 

 septa are thin membranes, placed nearly parallel 

 to one another. Their lengths are nearly in the 

 direction of the long axis, and their breadth is 

 nearly the semi-diameter of the body of the animal. 

 They are of different lengths, some being as long 

 as the whole organ. I shall describe them as be* 

 ginning principally at the anterior end of the organ, 

 although a few begin along the upper edge; and the 

 whole, passing towards the tail, gradually terminate 

 f>n the lower surface of the organ ; the lowermost 

 at their origin terminating soonest. Their breadths 

 differ in different parts of the organ. They are in 

 general broadest near the anterior end, answering 

 to the thickest part of the organ, and become gra- 

 dually narrower towards the tail : however they are 

 very narrow at the beginning or anterior ends. 

 Those nearest to the muscles of the back are the 

 broadest, owing to their curved or oblique situation 

 upon these muscles, and grow gradually narrower 

 towards the lower part, which is in a great measure 

 owing to their becoming more transverse, and also 

 to the organ becoming thinner at that place. They 



