228 NER\"ES TO DISSEMINATE ELECTRIC SHOCKS. 



these, as they pass into the skull, are carefully bridged 

 over with bone, to prevent any undue pressure upon 

 them from above; running under these bone bridges 

 we find them directly connected with the brain : they 

 start directly from the brain and begin their course at 

 once, just as do the electric w^ires from a telegraph 

 office through a hole bored in the wall of a house. The 

 brain itself is absurdly small, and is lodged in a cavity 

 apparently much too large for it. 



In order to j)reserve the parts in their proper posi- 

 tion, I made a cast of the torpedo, with its electric 

 battery, the moment I had finished the dissection. I 

 also made a cast of the fish before it was dissected. 

 These casts are at my museum, and will, I think, give 

 the visitor a good idea of the general appearance, as 

 well as the outward structure of this very wonderful 

 fish. I cannot determine in my own mind the exact 

 economy and mode of action of the complicated elec- 

 trical machinery of the torpedo. Does the brain create 

 the electricity and transmit it to the cells for storage — 

 as in a Leyden jar — or do the cells both secrete the 

 electricity and store it ? If this latter be the case, why 

 do we find such large nerves going to the brain ? This 

 may appear at first sight a trivial point, but the human 

 brain and nervous system being tlie most complicated of 

 all mammalia, we are tempted to reason as to the mode 

 of their operations, by comparing them with the same 

 machinery of nerves and brain as found developed in 

 lower forms of animal life. I do not know of any 

 mammal which has the power of secreting electricity. 

 This power is confined to this class of fish alone. These 

 fish are enabled to emit a certain number of shocks 

 only ; they then require rest for the accumulation of 

 more electricity. 



