578 



THE PHYSIOLOGY OF ELECTRICAL ORGANS. 



the change is thus strictly monophasic. This is well shown by the 

 character of the single excursion of the mercurial meniscus of the 

 capillary electrometer, produced by a single response of the excised organ 

 of Malapterurus, when in a low state of excitability. An examination of 

 this excursion, as photographed (see Fig. 294, A), shows that, after the 

 application of the stimulus at the time (x), a period of delay occurs 



succeeded by a rapid rise, due 

 to the development of the 

 change ; the subsidence is far 

 more gradual, and shows no 

 evidence of any counter elec- 

 tromotive effect bringing the 

 meniscus back to the initial 

 position, such movement as 

 exists being largely the dis- 

 charge of the charged capil- 

 lary through the short cir- 

 cuiting shunt. The character 

 of the excursion may be con- 

 trasted with that of B in the 

 same figure (Fig. 294), where a 

 counter-effect exists. This 

 was obtained in the following 

 way. The preparation was 

 connected with one pair of 

 condenser - plates, a second 

 pair of plates at 3 mm. dis- 

 tance being connected with 

 the capillary electrometer. 



FIG. 294. Outlines of records obtained by photo- Tyif-V, fV,je Q rr Q n mvmpnt hnth 



graphing the capillary electrometer. A, Mai- VYltri tniS airangement, both 



apterurus organ strip of low excitability; the development and the 



electrometer connected with caudal and cessation of a monophasic 



cephalic ends of strip, with short circuiting P h flTI ~p qVmnlrl -nrorhirp an 



shunt of 80 ohms. Temperature of strip cnan g e 



= 5 C. The nerve was excited by a single electromotive disturbance in 



induced current at the moment marked x. the condenser plates, the 



The single monophasic response commences at f nrTripr pansier a nhano-P nf 



O'Ol sec and is fully developed by 0-02 sec. B. torm ^ causing a Change Ot 



Same strip as that used in A, but connected one Sign, the latter one 01 the 



with a pair of condenser plates ; the electro- opposite sign. If a mono- 



meter was connected with another set of plates ^,,0,'p nhflncrp nprnrcs in thp 



at 3 mm. distance. The change in the organ P naS1 ' cnan g e oc 



commences at O'Ol sec. after the excitation organ preparation, it Should 



of the nerve producing a condenser charge ; it produce a diphasic effect in 



XT S Te m P pet 8 of %g 'he condensers connected with 



5C. Condenser 537 C.G.S. units. C, Same the Capillary. The photo- 



as B, but temperature of strip 30 C. Time of graphed records of the elec- 



commencement of response after excitation of t rnTr , p f pr p v piir<inn onrlinpd 



nerve, '006 sec. ; cessationlof response indicated J!? 1 * Cl PS1 ? n ' , ^"i. 



by discharge of opposite sign at O'OOS sec. m B, Fig. 294, IS clearly of this 



diphasic character, the sudden 



rise being succeeded by a sudden fall, which brings back the level of 

 the meniscus. The records A and B are both those due to responses 

 of the organ at a low temperature ; in C, Fig. 294, the record obtained 

 from the same organ at 30 C. shows that the response culminates 

 in TWTT sec - a ^ ter its commencement. 1 



1 Gotch and Burch, loc. cit. 



OZ'05 O/* 'OS 



-I 



03' 



Oi 1 (-. 



I 01" -02" 



