132 Cj7nparativc AnatcDty of the EhHrk Organs of the 



only dilb'ibutes branches to the nuifcles of the tail, but fend 5 

 fome alfo to llie elctlric organs. The different rami of this 

 nerve creep firfl: over the finfaces of thefe organs, and fprcad 

 and expand in their alveoli. It is thus that the vertebral 

 nerve*, by means of this deviation from their ufual route, 

 and of an augmentation of volume, become in the gvmnotus 

 c!e(itricus fo many iullrunicnts capable of flrikiiig with death, 

 or at leaft with torpor, all thofe animals which they touch. 



The cleftric organ of this fiOi being placed under the tall, 

 and in a part which confequently Is removed from the prin- 

 cipal fvftemsof life, it was difficult to conceive what were the 

 nerves which could proceed thither. The limplcfl. combina- 

 tion was to deduce them immediatelv from the ipinal marrow ; 

 and this, indeed, is that which v/e fee realized in the gym- 

 notus clc6lricus. 



The fimplicity of the means employed by nature is ob- 

 ferved in a manner ftill more particular in the filurus elec- 

 tricus. This filli differs almolt as much from the gymnoti 

 as from the rays, and therefore we muft expeft a quite dif- 

 ferent organization. 



It is, indee-d, neither on the fides of the head, as in the 

 torpedo, nor below the tall, as in the fpccies we have de- 

 fcribed, that the eleftric organ of the (ilurus eleclricus is 

 found. It is extended all round the animal; it exKls im- 

 mediately below the fkln, and is formed by a confiderable 

 collection of cellular tlifue, fo thick and compait, that on the 

 iirR view it might be taken for a itratum of lard : but when 

 clofely lnfpc6ted it is obfeived that this organ is compofed 

 of real tendinous or aponeurotic fibres interwoven with each 

 other, and which by their different croffings form a reticu- 

 lation the mefhcs of which are not diitinttlv viilbie without 

 the help of a magnifvlng glafs. The fmall cells or alveoli of 

 this reliculatlon are lilled with an albumlno-gelatinous mat- 

 ter. Thcv are prevented from communicating in tlie infide 

 by a very ftrong aponcurofis, which extends over the whole 

 eledlric reticulation, and which adheres to it fo clofely that 

 it cannot be feparatcd without iearing it. This aponeurofis 

 in other refpefts adheres to the mufcles only by a thin cel- 

 lular tiffuc of little confiftence. 



The nervous fy[lem, which corapletes this ele6lric organ, ha» 

 no more relation with the nervous branches which we exa- 

 mined in the torpedo and the gvmnotus than the tubes of 

 the latter have with the peculiar covering of the lilurus elec- 

 tricus. Thefe nerves proceed from the brain ; they are the 

 fame as thofe which my friend Cuvicr has obfersed in all 

 filbcs to proceed under the lateral line: but thel'e two nerves 



of 



