Electro -motive Changes accompanying Activity in Mammalian Ureter. 229 
electrodes are placed at a distance of 1 cm. from each other ; in Fig. 3 they 
are 2 cm., and in Fig. 4, 3 cm. apart. 
When the electrodes are separated by a considerable distance from each 
other, curves are recorded of the form given in Figs. 5 and 6. These 
records were obtained from the ureter of the anaesthetised monkey, where 
the non-polarisable electrodes were applied, the right-hand one close to the 
pelvis of the kidney, and the left-hand one close to the bladder. The ureter 
was not perfused, but a cannula connected with a reservoir of warm Ringer's 
solution was inserted into the substance of the kidney and the pressure 
raised. This produces a continuing stimulus, which gives rise to rhythmical 
peristaltic waves in the ureter. 
The variations accompanying these waves (Figs. 5 and 6) show summits 
which are lettered Qr^ B,.^ Qi^ and Bi, Fig. 6 shows in addition an upward 
summit which is not always present, and which I have lettered x. 
Occasionally peristaltic waves arise at the renal extremity of the ureter 
which are not propagated along its whole length. Fig. 7 gives the electrical 
variation accompanying one of these waves in the monkey's ureter, and may 
be taken as indicating the electrical change under the right-hand or proximal 
electrode alone. I have lettered the summits Qr, Br, and Tr. 
Diagram Fig. 8 shows how the complete variations such as Figs. 5 and 6 
are produced by the summation of two oppositely directed variations such as 
Fig. 7, separated by a time interval, and affecting the right- and left-hand 
electrodes respectively. 
Orbeli and Briicke* have published curves from the mammalian ureter, 
two of which are indicated here for the purpose of comparison as Figs. 9 and 
10. I have inverted these curves in order to bring them into accord with the 
usual manner of presentation. 
Fig. 9 records a wave which disappeared before reaching the second 
electrode. The deflection V appears to represent Q, and to represent B. 
There is no sign of summit T. Fig. 10 records a complete wave, ifg appears 
to represent Bi^ and N to be the wave which I have found occasionally 
present and lettered x. 
It appears to me that it would not be possible from an examination of 
these curves of Orbeli and Briicke to deduce the form of the electrical change 
under one electrode, as can be done from the curves recorded in this paper, 
nor to show how the complete variation is obtained by summation, but 
Orbeli and Briicke' s curves show that the first effect of the peristaltic wave 
on reaching the proximal or right-hand electrode is to make it relatively 
positive to the distal electrode. 
If, as appears to be indicated by the results recorded in the present 
* Pfliiger's Arch., 133, 1910, p. 341. See Bayliss' Principles of General Physio- 
logy, p. 651, 
