THE OPALINID CILIATE INFUSORIANS. 437 



ProtoopaZina and Cepedca]^ asymmetrical, many round nuclei or a 

 single bipartatite nucleus" [often two nuclei, though none of the 

 flat species known at the time of this paper had two nuclei or a 

 double nucleus ; nuclei frequently not round.] 



Kunstler (1903) discusses and figures the pellicle of Opalina 

 [Cepedea] dimidiata. 



Birukoff (1904) says that under stimulation by direct electric cur- 

 rent " Opalina " in sodium chloride solution moves to the anode ; 

 under stimulation by alternating electric current the Opalinae lie 

 near the electrode, the Paramecia in a line outside the Opalinae. 



Entz (1904), same paper as Entz (1901). 



Gineste (1905) discribes again observations by Kunstler and him- 

 self upon the structure of the protoplasm in '''■Opalina " \Cepedea'\ 

 dimidiata. [See Claoue (1919), page 445 of this paper, also see 

 Metcalf (1909) for comments upon these often published results of 

 Kunstler's and Gineste's studies.] 



Birukoff (1906) briefl}^ discusses the work of Wallengren and 

 Statkewitsch upon galvanotaxis in Opalina. Opalina in physiologi- 

 cal salt solution, under stimulation, invariably moves to the anode, 

 a reaction the reverse of that seen in Paramecium. The difference 

 in behavior may be due to the anterior end of Paramecium being 

 more sensitive, while the two ends of Opalina are equally sensitive. 

 In an acid medium Opalina moves to the cathode. The sensitiveness 

 of Opalina may be increased in an acid medium. " Die Ubersicht 

 der neuesten Arbeiten iiber die Galvanotaxis fiihrt zur unum- 

 gtinglichen Schlussfolgerung, dass die allgemeine Errogbarkeit und 

 kataphorischen Stromwirkung (Stromingsstrome) in Wirklichkeit 

 die beiden Hauptfaktoren der Galvanotropismus sind." 



Schouteden (1906) reviews Shewiakoff's (1896) paper. 



Mengarini, Margherita Scala, and Alberto Scala (1906) report 

 observations upon the effect of sodium chloride solutions upon " (9/>(r- 

 Zwa," producing change of form, the permeability being different 

 at the two ends of the body. 



Galli-Valerio (1907) reports the presence of Opalina ran^amm in 

 Rana esculenta- [new host record], R. temporaria., Bomhina bomhina 

 [new host record] and Triturus alpefHs [new host record], all from 

 the Swiss canton Vaud. 



Klopstocz (1907) gives a brief report of Neresheimer's (1907) 

 work. 



Mengarini and Scala (1907) report investigation of the action upon 

 " Opalina " of solutions of sodium carbonate, sodium chloride, and 

 potassium carbonate. Many experiments, fully described, statements 

 being made as to the time the animals live in the different solutions, 

 as to the extrusion of posterior globules, and as to color reactions. 



