580 



THE PHYSIOLOGY OF ELECTRICAL ORGANS. 



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Fig. 296. — Outlines of excursions of capillary electrometer records when the capil- 

 lary is connected to one pair of condenser-plates, and another pair, at 3 mm. 

 distance from these, is connected with the two ends of a strip of Malapterurus 

 organ. In A the organ was excited by stimulating the nerve with a single 

 induced current at the moment marked x. The temperature of the strip was 

 15° C. The secondary responses occur at an average interval of 0'0076 sec. ; 

 initial period of delay, 0"0080 sec. In B the organ strip was excited directly 

 by an induced current (heterodromous) ; the temperature of strip was 25° C. ; 

 initial period of delay, 0"0035 sec. ; average interval between secondary 

 responses, 0'0045 sec. 



response passing from the head to the tail end of the strip must be of 

 opposite sign to that of A. When the two strips, A and B, are suc- 

 cessively connected with a capillary electrometer, records of their 



n, . responses are ob- 



^Eocc- of nerve tained> of which 



the curves A andB 

 in Fig. 298 are an 



Head illustration. It is 

 end obvious that the 



of organ lower curve is the 

 response of B, due 

 to the excitatory 

 change of A tra- 

 versing its sub- 

 stance. The re- 

 sponse of the 

 secondary prepar- 

 ation B, differs 

 from that of the 

 It is clear, there- 



f/c ad, 

 end 



of organ} 



Capillt 



laru 

 eircn 1 r 



Capillary 

 circuit 



Fig. 297. 



primary one A, in having an extra period of delay. 



