54 PROTOPLASM OF PROTOZOA 



of various salts and salt antagonisms upon the consistency of Amoeba 

 protoplasm. In general it has been found that sodium and potassium 

 ions tend to increase the viscosity of the internal protoplasm, while 

 calcium and magnesium tend to lower it. However, Heilbrunn and 

 Daugherty (1932, 1934), have found that this does not hold for the 

 plasmagel (i.e., outer layer) of A. proteus. Here calcium produces a 

 pronounced stiffening of the cortical gel, and this effect tends to be 

 antagonized by Na, K, and Mg. Potassium has the strongest liquefying 

 effect, Mg next, and Na the least action. The degree of reaction, par- 

 ticularly the antagonism of salts, seems to vary somewhat, depending 

 upon the hydrogen-ion concentration (Pitts and Mast, 1934). 



Greeley (1904) observed that KCl coagulates or increases the 

 viscosity, whereas NaCl liquefies or decreases the viscosity of the proto- 

 plasm of Paramecium. Heilbrunn (1928) reports that unpublished 

 work of Barth shows that lithium salts cause a coagulation or increase 

 in viscosity of the protoplasm of both Stentor and Paramecium. Heil- 

 brunn (1928) found that sodium, potassium, ammonium, and lithium 

 chlorides all cause coagulation of Stentor protoplasm and that weak 

 solutions of HgClg produce a coagulation of the protoplasm of Euglena. 

 The effect of salts upon reproduction in Amoeba has been studied by 

 Voegtlin and Chalkley (1935) and by Butts (1935). Oliphant (1938) 

 observed that potassium, lithium, sodium, and ammonium salts induce 

 reversal in the direction of the effective beat of the cilia of Paramecium, 

 whereas calcium and magnesium do not. The reversal in direction of the 

 beat of the cilia is thought to be associated with an increase in viscosity 

 of the cytoplasm. See also the work of Spek, 1921, 1923, and 1924, 

 on the action of various salts on Actinosphaerium, Opalina, and other 

 Protozoa. 



Chambers and Howland (1930) have cut or torn Spirostomum 

 in CaCl, solutions; the exposed protoplasm coagulates into a dense mass 

 which the uninjured part of the organism pinches off. Injection of 

 CaClg produces localized coagulated regions which are pinched off. 

 Potassium chloride and NaCl cause liquefaction. Ephrussi and Rap- 

 kin (1928), however, report that CaClg facilitates "I'explosion" of this 

 ciliate; KCl and NaCl render explosion more difficult. 



Chambers and Howland (1930) have further performed injection 

 and immersion experiments with A. eichhornii, a heliozoon with grossly 



