PRIMARY INHIBITION OF CILIARY MOVEMENT - 413 
11h. 28m. Today, too, total inhibition of the ciliary activity 
can be produced by mechanical irritation of the edges of the 
mouth. At the same time there is a quite insignificant retrac- 
of the rows, but this by itself is not sufficient to explain the 
stoppage. 
11 h. 40 m. It is noticed that the animal raises itself once or 
twice into a vertical position with the sensory pole upward, a posi- 
tion, however, that it is unable to retain. 
11 h. 45m. A ‘spontaneous’ and complete stoppage of the 
swimming plates, lasting about } minute, was observed. 
12 h. 34m. Electrodes are immersed into the cuvette where 
the animal is at the bottom. It is very difficult to get the animal 
into the proper direction in relation to the electrodes because of 
its rotatory movements (caused by two adjacent rows striking 
both with less frequency and with less amplitude than the rest). 
Temperature in the cuvette, 17.0°. 
12h.37m. Longitudinal oro-central current. With a current 
of density 0.47m.amp./cm.? there is no perceptible inhibition. 
With 0.93 m.amp./cm.? there appears a long total inhibition. 
12h.45 m. With 0.93 m.amp./cm.? stoppage for 14 seconds 
except for two waves on one row. 
12h. 47 m. With 1.47 m.amp./cem.? there is total stoppage 
even after 30 seconds. The animal is transferred again to the 
aquarium. 
3h. The water in the aquarium is replaced by fresh sea-water. 
5h. 46m. The ciliary activity is more lively and especially 
more continuous than in a normal animal. The animal whirls 
around in the aquarium and now and again knocks against the 
wall of the aquarium with its mouth, but no total stoppage is 
observed on account of this. 
2/8. 6 p.m. The conditions are the same as at 5h. 46 m. 
yesterday. 
3/8. On an examination with a Zeiss’ binocular lens of high 
magnifying power it was found that the defect caused by the op- 
eration had healed. Six of the ciliated furrows have no connec- 
tion with each other; two, on the other hand, are connected and 
in the two corresponding rows the waves are synchronous. The 
