430 ELECTRO-PHYSIOLOGY CHAP. 



and their nerves, which take much longer in becoming paralysed. 

 With very strong doses of curare, Steiner (33), and later on Ranvier 

 and Boll (4 c, p. 194), as previously Marey, succeeded in 

 paralysing not merely the motor but also the electrical nerves 

 in Torpedo. The poison, of course, took effect more quickly when 

 injected directly into the blood, than when it was given subcutane- 

 ously or through the abdominal cavity. According to Babuchin, 1 

 cc. of a 2 / Q solution is sufficient, in the first case, to induce com- 

 plete motor paralysis in a full-grown torpedo in 1520 min., while 

 the electrical organ is still reflexly excitable ; in subcutaneous 

 application three times the dose was required. Malapterurus was 

 found to give the same reaction. Schonlein states that in order 

 to obtain a complete effect, in which case the direct excitability 

 of the organ also disappears completely, it is necessary to give 

 enormous doses (15 cc. of a 4 / o solution = 6 decigr. curare), even 

 when the poison is injected directly into the blood (anterior gill 

 .artery). Immediately after injection of the first 5 cc., one or 

 two sharp discharges occur with commencement of an opistho- 

 tonus, followed by a rapidly -decreasing tetanus of the organ. 

 Weak reflex discharges, however, continue for some time on 

 touching the animal, unless a second and even third injection is 

 given, after which it is still necessary to wait some 20 min. 

 Schonlein inclines to make the slow circulation responsible for 

 this pronounced immunity to curare. Armand Moreau (23) 

 could not discover any action of curare upon the electrical nerves 

 of Torpedo. It is easy to paralyse small torpedoes so completely 

 by subcutaneous injections of about |- cc. of 1 % solution, that 

 there is no sign of movement on stimulating the cord or motor 

 nerves ; whereupon mechanical excitation of the skin will still effect 

 reflex discharges of the same strength as before the intoxication. 



Sachs made two curare experiments on Gymnotus, showing 

 complete paralysis of the electrical nerves with very strong doses. 

 Tetanisation with normal distance of coil then gave hardly any 

 perceptible effect on the galvanometer, while direct stimulation 

 still called out very marked deflections, as also the application of 

 ammonia to the long section of the organ -preparation. We 

 cannot, however, regard these observations as proof of the 

 independent excitability of the electrical plates, which Schonlein 

 regards, on the strength of the curare experiment, solely as 

 " nerve-endings." 



