408 GUSTAF FR. GOTHLIN 
EXPERIMENTS AND OBSERVATIONS 
1. Beroé, 23 mm. long, caught the previous day. 'Tempera- 
ture in the cuvette 15.3°C, The animal is at the bottom of the 
cuvette half-way between the electrodes; ciliary action is ob- 
served in all the rows; frequency about one wave per second. 
Longitudinal oro-central current. Closure of a current with a 
density of 0.92 m. amp./cm.? causes no perceptible inhibition. 
If, on the other hand, a current of density 1.91 m.amp./cm.? is 
closed, it causes total stoppage of the movements of the swimming 
plates. 
Longitudinal centro-oral current. Neither a current of 1.91 
m.amp./cm.? nor of 2.7 m.amp./em.? nor of 3.55 m.amp./em.? 
completely stops the ciliary movement, although the two latter 
cause a contraction of the aboral part of the animal, accompanied 
by a drawing in of the rows in the same region. 
2. A Beroé specimen, 26 mm. long, caught the day before. 
Temperature in the cuvette 16°C. All the rows show a ciliary 
movement, but the frequency varies rather considerably. 
Longitudinal oro-central current. Starting of a current 0.375 
m.amp./em.? does not inhibit in any decided way the movements 
of the swimming plates. A current of 0.77 m.amp./em.?, on the 
other hand, produces total inhibition. The stems of the swim- 
ming plates in all the rows stop and remain in a compressed posi- 
tion with their apexes directed toward the oral pole. When the 
current is broken after about a half minute, it appears that the 
ciliary apparatus is still quite motionless for a few seconds after 
the breaking, but then resumes its regular activity. 
The animal is then tested with an induction current, which is 
also conducted, in the longitudinal direction of the animal, 
through the same electrodes from a Blix cosinusinductor driven 
by a Jungner accumulator (1.4 volt). The frequency of the 
waves was calculated in one row by means of a stop-watch. 
1. Frequency without any current, 15/21 sec. = 43 per min. 
Current of strength indicated 34, frequency 15/21 sec. = 43 per 
min. 
