STRUCTURE OF PROTOPLASM OF PARAMOZCIUM. 



their state of fine mixture or suspension, which is always char- 

 acterisic of motile protoplasm, and the protoplasmic particles 

 tend to fuse into a spongy coagulum or " gel" from which the 

 cell sap continually escapes, until a complete separation of the 

 two elements is brought about. This fusion of the protoplasmic 

 particles may result in the formation of two varieties of coagu- 

 lated structure. The fused particles may appear as spherical 

 bodies of proteid material, unconnected but closely massed to- 

 gether in such a way as to form an exceedingly dense coagulum 



FIG. 3. Coagulated protoplasm of FIG. 4. Another type of coagulation 



Paraituvciam under T V oil-immersion. A viewed under the T \ oil-immersion. The 



dense coagulum formed after an expo- result of a ten hour residence in w/8oo 



sure to w/32O CaCl. 2 for twenty-four HC1, showing a trace of the reticular 



hours. structure. 



(see Fig. 3). Or the protoplasmic particles may fuse into fibrils 

 or anastomosing threads which form an incomplete network, 

 holding the cell sap in its interstices. The fibrils may eventually 

 become thicker and transform the network into a relatively 

 solid coagulum (Fig. 4). These last forms of coagulated struc- 

 ture are very similar to the network formations obtained by 

 Hardy in organic colloids and various protoplasmic tissues by 

 the action of fixing agents, and have been formerly supposed to 

 be characteristic of living protoplasm. As in Hardy's experi- 

 ments these fibrillar or reticular structures never appear in the 

 living protoplasm of Paramceciuiu, but are solely an incidental 

 result of the process of coagulation by chemical or other means. 

 The salts and bases in the second column of the table, which 

 produce a common liquefaction of the protoplasm of Paramcecium 

 through the action of a predominant anion, are effective like the 



