12 



A. W. GREELEV. 



FIG. I. Normal protoplasm of Para- 



m cccii tn i. 



T X 5 in. oil immersion. 



It will be seen by an examination of the table that the activity 

 of any of the salts, as is shown by the strength of solution re- 

 quired to modify the structure of 

 the protoplasm of Paramoccinin, 

 varies directly with their valence. 

 The acids and bases are much 

 more powerful in their action 

 than any of the salts of a similar 

 valence, probably because of the 

 known disproportionate kinetic 

 energy of the hydrogen and hy- 

 droxyl ions. 



All the acids and salts found 

 in the first column of the table, 

 which agree in coagulating the 

 protoplasm through the action of the predominant cathion, effect 

 changes in the protoplasm so similar as to be practically indis- 

 tinguishable even under a high magnification. The less active 

 solutions, such as KC1 and MgSO 4 , do not produce quite so 

 dense a coagulum as the others, and the reaction is considerably 

 slower. But in all the bivalent and trivalent salts and the acids, 

 a distinct clouding of the protoplasm can be observed within 

 thirty minutes after the paramcecia have been immersed in the 

 solution. This clouding of the protoplasm increases and is ac- 

 companied by a shrinking of the cell owing to a loss of water, 

 until within a few hours, the whole cell is reduced to a subspher- 

 ical mass of densely opaque 

 protoplasm (see Fig. 2). The 

 changes are identical with 

 those produced by a lower- 

 ing of the temperature. 



An examination of the pro- 

 toplasm with a one-twelfth 

 inch oil-immersion lens re- 



FIG. 2. A Paramcecium in w/32O MgCl,, 



, . e , showing a typical coagulation of the pro 



veals the fact that the cloud- 



toplasm. 



ing of the protoplasm is due 



to a separation of the two elements of the protoplasm, the cell 



sap and the protoplasmic granules. These two elements lose 



