v ELECTROMOTIVE ACTION OF EPITHELIAL AND GLAND CELLS 503 



variation of the entering current, which appears whether the 

 stomach is excised or in situ., in mammals, after a transitory 

 increase of the entering current, there regularly appears a negative 

 variation which can reach such proportions that the current not 

 only sinks to zero, but goes beyond it in the reversed direction, 

 so that the now outgoing current may, under certain conditions^ 

 become as strong as the original ingoing current. That this is 

 not, as might have been supposed, an action of secretory nerves, 

 but merely an after-manifestation of the disturbance of the cir- 

 culation due to the slowing or stand-still of the heart, and, in the 

 first degree, to the marked fall of Uood-pressure, is very easily 

 determined. It appears not merely from the time coincidence of 

 the latter and the negative variation, but more particularly from 

 the fact that whatever depresses blood -pressure locally or in 

 general, also tends to diminish the ingoing current of the stomach. 

 This applies to every severe loss of blood, and notably still more 

 where clamping of the aorta has temporarily produced a complete 

 anaemia of the stomach. The current diminishes almost at the 

 moment when anaemia sets in, just as with vagus excitation, to 

 recover again when the blood-stream is freed. Here, as in the 

 first case, it makes no difference whether the vagi have previously 

 been divided at the neck or not. Slow, rhythmical compression 

 and release of the aorta as best effected by cutting away some 

 of the ribs on the curarised, artificially breathing animal produce 

 similar rhythmical variations of the stomach current. Every 

 protracted anaemia of the mucosa retards the increase of the 

 current very considerably, until finally recovery is no longer 

 possible. In dyspnoea too, a marked negative swing always 

 follows upon the temporary increase of normal electrical action. 

 The simultaneous tracing of the blood-pressure on the kymograph 

 after double vagus section, proves that there is no immediate 

 coincidence between the alterations of the arterial mean pressure 

 in the carotid and the variations of current, since the negative 

 phase is usually developed at the beginning of the dyspnoeic 

 increase of pressure, and continues after blood -pressure has 

 returned to its normal height by renewal of artificial respiration. 

 The positive variation, on the contrary, occurs between the begin- 

 ning of dyspnoea and the first increase of pressure. It is 

 obvious that this reaction cannot be forthwith interpreted in the 

 sense that the progressive venosity of the blood caused the fall of 



