THE TORPEDO. 85 



Number of columns in each organ various. 



within these limits they occupy the whole space 

 between the skin of the upper and under sur- 

 faces. Each organ is attached to the surround- 

 ing parts by a close cellular membrane, and also 

 by short and strong tendinous fibres, which pass 

 directly across from its outer edge to the semi- 

 circular cartilages. They are covered above and 

 below with the common skin of the animal, 

 under which are longitudinal fibres spread en- 

 tirely over them. Each organ is about five 

 inches in length, and at the anterior end about 

 three in breadth. They are composed of perpen- 

 dicular columns, reaching from the upper to the 

 ndcr surface, varying in length according to the 

 thickness of the parts of the body, from an inch 

 and a half to half an inch ; and their diameters 

 are from a fourth to a fifth of an inch. The 

 coats of the columns are very thin, and almost 

 transparent. The number of columns in each 

 organ varies considerably in different animals. 

 That of one that Mr. Hunter presented to the 

 Royal Society was about four hundred and se- 

 venty ; but in a very large torpedo the number 

 of columns in one organ was 1182. These co- 

 lumns were composed of films parallel to the 

 base of each, and the distance between each of 

 the columns were one hundred and fiftieth part 

 of an inch. 



" If," remarks Mr. Hunter, (Phil. Trans.) 

 " we suppose these films to be charged with 

 electricity, and to be the 300th part of an inch 



