Opalina. 335 
large number of sections examined, but they are smaller than the 
meganuclei [no] which, as in other forms, increase considerably [very 
slightly] in size before division.” [Each nucleus of Opalina seems 
to be functionally comparable to both micro- and macronucleus of 
higher Cirliata, but to be homologous with each, both the nuclei of 
Ciliata being phylogenetically complete nuclei. | 
WALLENGREN (1903) describes the form of the body of O. ranarum 
(Text Fig. XVI) [which has its very broad anterior end bent “to the 
right”]; the arrangement of its cilia; the normal movement of the 
cilia in which the cilia that he along the “anterior half of the 
right side” [corresponding to the morphological anterior end] beat 
forward [morphologically backward and toward the left] while all 
the others beat backward, the animal thus turning over to the 
right as it swims; he describes and analyzes the reactions of the 
cilia under electric stimulation, which cause the animal with a weak 
current to swim forward toward 
the anode, with a stronger current 
to swim forward toward the 
kathode, with a still stronger 
current to swim backward or 
sidways toward the anode. 
Mater (1903) describes care- 
fully for O. ranarum the pellicula, 
and the cilia and _ their basal 
granules. He denies the connec- 
tion of the cilia with a network 
of subcuticular fibrils such as 
TOnNIGES describes, ascribing the 
appearance of the transverse lines 
observed to ridges in the pellicle. 
[My study confirms TOnniGEs as 
to the presence of a sub-pellicular 
network in connection with the. sabi } 
cilia, though T would not aseribe meting the detonate main 
the movement of the cilia to the the direction in which the animal turns 
contraction of the fibrils of the (feathered arrow). Thee dotted lines 
network. The network seems across the body do not indicate the 
more likely to be useful for the lines of insertion of the cilia but the 
eoordination of the movements of 2% of contraction of the cilia. What 
dhctority Miers ate __, JL interpret as the morphological anterior 
Ne CIA. | MATER OPPOses LONNIGES ‘end stretches form -+ to + and is in- 
description of the alveolar struc- dicated by the dotted index line. 
Text Fig. XVI. 
WALLENGREN’s figure of O, ranarum, 
