432 GUSTAF FR. GOTHLIN 
the practically immediate appearance of primary extinguishing 
of certain ciliary waves during their course through the rows— 
in the experiment with a dilute solution of ether—be possibly 
due to the ether having in this short time penetrated into and 
directly extinguished the conduction of the impulse between the 
swimming plates. For, if this were the case, we ought not to 
find in the same experiment that the waves gradually get back 
their full extension, although the concentration of the ether is 
not changed during this time. 
In both cases we must have been concerned instead with a 
transmitted effect that was presumably produced from receptory 
apparatuses on the surface of the animal which have been stimu- 
lated, in one case mechanically, in the other case chemically and 
osmotically by the dissolved ethyl ether. In the case of the gal- 
vanic current, it is more probable that it stimulates nervous or 
neuroid connections between the receptory apparatuses and the 
meridional rows. The first impression produced by experiments 
3 and 6, inasmuch as in them waves from the aboral pole proceeded 
to a point in the course of each row and below it expired alto- 
gether, is that the inhibitory impulse transmitted from the recep- 
tory areas to the meridional rows affects the neuroid conductive 
path between the plates and not the plates themselves. It 
seems, however, to be difficult to exclude the last-mentioned 
alternative altogether, as when a plate in a meridian row stops it 
is usual in Beroé that all those situated orally to it also stop. 
In any case, it is necessary, if the primary inhibitory effect in 
all the occurring cases is to be explained, that from the ectoderm 
and to each row of swimming plates there should proceed paths 
which from a physiological point of view are characterized by the 
fact that they transmit cilio-inhibitory impulses and whose ana- 
tomical substratum must be denoted as cilio-inhibitory nerve 
fibres, provided they prove to be composed of elements which, 
not only physiologically, but also morphologically, have the 
character of nerve elements. That primary total inhibition of 
the swimming plates can be brought about from the edges of the 
mouth more easily than from other places on the surface of the 
body seems to agree with the fact that these edges are furnished 
