PRESENT STATE OF ORGANIC ELECTRICITY. 341 



therefore, wills a shock, or when, through the reflex action 

 of its electrical nervous centre, a shock is induced, a sudden 

 and copious nervous influx flows over the under surfaces of 

 its electric diaphragms, the upper surfaces are thrown into 

 an opposite electrical condition, and a current is the conse- 

 quence. 



Pacini refers the structure of the battery in Gymnotus to a 

 ternary type. This type presents a negative element, which 

 consists of the fibrous layer on which the nerves ramify, to- 

 gether with the fluid which it bounds below; a positive ele- 

 ment formed by the ridged vasculo-cellular layer, and the 

 conducting inter-diaphragmatic fluid. The vasculo-cellular 

 layer predominating in this ternary type over the nervous, 

 Pacini conceives the electricity to be evolved in the organic 

 actions of the vasculo-cellular layer under the influence of the 

 nerves. In other words, the will of the Gymnotus, or the re- 

 flex action of its electrical nervous centre, directs an influence 

 along the nerves of its batteries over the fibro-nervous layer, 

 which suddenly exciting the nutritive or other organic actions 

 of the highly-developed vasculo-cellular layer, an electrical 

 disturbance is produced, with an opposite electrical condition 

 of the fibro-nervous and vasculo-cellular layers of the dia- 

 phragms, and consequently a current through the series. 

 Pacini compares the wide-meshed fibrous layer, on the under 

 surface of which the nerves ramify, to the hollow cylinder of 

 porous clay, which in a Bunsen's or a Grove's galvanic ar- 

 rangement separates the negative from the positive elements. 



The Batteries of the Fish are Independent Electromotor 

 Structures. From the observations of Pacini, the terminations 

 of the nerves appear to form important elements in the 

 structure of the battery. On physiological grounds, however, 

 it appears probable that the peculiar texture of the electric 

 diaphragm is itself the seat of the electromotor power. As 

 an ultimate muscular fibre contracts, although entirely sepa- 



