336 M. M. Mercatr 
ture of the refractive spherules, saying they are homogeneous. 
[BEzZENBERGER and I confirm TOnnicEs.]| Mater opposes TOnNIGES’ 
description of the ectoplasma as containing large alveoles, saying 
that its alveoles are as small as those of the endoplasma. |My work 
confirms TONNIGES. | 
Veneztant (1904) divided cultures of O. ranarum into two 
exactly equal parts and placed a tube containing '/,, gram of active 
radium bromide in one dish and none in the other. In ten experi- 
ments when the culture medium was 0.5"/, or 0.6°/, sodium chloride 
solution, and in four experiments when the animals very kept in 
ordinary water (not distilled), the Opalinas in the culture containing 
the tube of radium bromide remained active longer than in the 
corresponding unstimulated cultures. The author says it is doubtful 
whether the longer continued activity of the Opalinas is due to the 
direct effect of the radium upon their protoplasm, or to same 
modification of the density or chemical composition of the culture 
media. 
STaTKEWITscH (1904) finds that O. ranarum does not react at all 
to weak constant and induction electric currents (0.5—1 MA), with 
stronger currents (3-4 MA) they generally swim slowly toward the 
kathode. With rather strong currents (2.3 or 4 MA) they often 
swim slowly toward the anode; sometimes they first approach the 
anode and later turn and approach the kathode. Often with a weak cur- 
rent they start toward the kathode, but, without reaching it, turn 
back and swim in various directions through the culture. In the 
latter cases they probably become accustomed to the stimulation. 
The character of the reaction depends on the strength of the current. 
In another paper (19V5) StarkEewitscH mentions O. ranarum in 
a discussion of the reactions of cilia in the Cv/iata to electric cur- 
rents. 
BEZZENBERGER (1904) describes five new species of Opalina from 
Asiatic frogs and toads (0. macronucleata, O. lanceolata, O. coracoidea, 
O. lata and O. longa}, giving many anatomical details. He figures 
mitosis in O. macronucleata and O. lanceolata (cf. Text Fig. V, page 250). 
For 0. longa he describes very peculiar elongated rod-shaped basal 
granules of the cilia, reaching from the pellicula through the whole 
ectoplasma and as far again into the endoplasma. The ectoplasma 
is described as having a zone entirely without demonstrable struc- 
ture. [His figure was evidently drawn from very poorly preserved 
material in which it was probably not possible to recognise the real 
structure of pellicula, cilia, basal granules, or ectoplasma.| The proto- 
