ON THE CLASSIFICATION OF CILIATE 
INFUSORIA. 
DR. V. STERKI. 
AFTER so eminent a naturalist as Bütschli has modified 
Stein’s system of Ciliata, it may appear rather assuming if I 
venture to propose some changes. It is done because my 
views have long been held, and have been confirmed as the 
years passed. 
In the first place, it seems that the Peritricha are of an 
organization quite different from that of all other ciliates. The 
formation of the anterior part, peristome, mouth, etc., is unique, 
although having some resemblance to that of the Stento- 
rina. There is no adoral zone with transverse rows of cilia 
like that in Heterotricha and Hypotricha, as has recently again 
been asserted by Delage et Herouard.! The arrangement of 
the muscular elements in the ectoplasm, or myonems, is quite 
different. The formation of a temporary posterior girdle of 
cilia for locomotion, in the most typical Peritricha, and even 
the permanent one in some others, is a very distinguishing 
feature. And a distinction of highest order is their mode of 
fission in the longitudinal axis,? or by gemmation. This char- 
acter has been explained in various ways, and some have tried 
to bring it in conformity with the transverse fission in the 
other groups. Nevertheless, it remains different, and shows, 
combined with the other features noted above, that this group - 
is of quite another type, or phylum, the more so if we add the 
peculiar phenomena of conjugation. The remaining Ciliata 
differ from the Peritricha in regard to these characters, and 
they resemble one another in respect to the most significant 
of them 
i 1 Traité de Zoologie Concrète. I. La Cellule et les Protozoaires. Paris, 
1896, 
tthe ust tié noted, sa that in all groups the direction of the division is 
across that of the myonems. 
