ELECTRICAL FISHES 409 



current from the disturbed eels, and dead fish and frogs then appear 

 at the surface." 



As regards the nature of the effect produced by a not im- 

 moderately strong discharge, it was remarked by Sachs that it 

 exhibited a strong resemblance to the brief action of the sliding 

 inductorium with so-called vagus electrodes (hook -shaped metal 

 wires). " There is an unmistakable sensation of persistence, of 

 oscillatory character in the shock." In the Gi/mnotus the 

 shock, according to du Bois-Eeymond (4 d, ii. p. 619) is "less 

 sharp than that from a Ley den jar, and rises more gradually ; 

 it is often possible to distinguish several maxima," 



" The discharge of Malapterurus is surprisingly powerful in com- 

 parison witli its size. If the head and tail of a vigorous fish are 

 touched in water with the fore-finger, the shock does not indeed reach 

 beyond the middle-finger joint, but if the animal is grasped with 

 well-moistened hands a sharp shock is perceived as far as the elbow. 

 AVith the secondary coil pushed right up, and a Grove's cell in the 

 primary circuit, a break shock taken through the hand is about 

 equal to a " strong " shock from a fish. Babuchin received such 

 a powerful discharge from one-half of the electrical organ of 

 Malaptcrurus, on exciting the oblongata, that " he remained uncon- 

 scious for several minutes." He points out the difference in 

 sensation between the shocks of Torpedo and of Malapterurus. 

 The shocks from the former are, as it were, blunter and duller, 

 those from Malapterurus are sharper, more stinging and penetrat- 

 ing ; briefly, the difference is the same as that between the currents 

 of the primary and the secondary coils between the extra-current 

 of the principal, and the break shock of the secondary circuit. 

 Mere contact with the point of a barbel of Malapterurus is enough 

 to cause a sharp prick in the finger. This is never the case with 

 Torpedo. Du Bois-Eeymond suggests that the difference may be 

 due to the different mode of innervation of the organ in the two 

 cases. " At the half of the Malapterurus organ (which is inner- 

 vated by a single ganglion-cell) the shock of the most distant plate 

 is separated from that of the nearer ones only by a minute fraction 

 of a second, as required for the wave of induction to travel the 

 length of the organ. In the organ of Torpedo, on the other hand, 

 the duration of the discharge is determined by the time required 

 for the excitation of the entire electrical lobe. And this period, 

 judging by what we know of the transmission of any stimulus 



