

372 BOTANICAL GAZETTE [November 



case of the cytoplasm of the Aster ias egg which Kite describes as 

 "a quiet translucent gel ... . which can be cut into small 

 pieces") Kite was either dealing with dead protoplasm, or else 

 the expressions used convey an impression which he himself did 

 not mean. In none of the material worked upon have I been 

 able to "cut" the living protoplasm into small pieces. 



There is no doubt that when one is able to cut protoplasm 

 "into pieces as small as the limit of microscopical visibility/' the 

 protoplasm is no longer normal. It is not clear just what degree 

 of viscosity Kite wishes to attribute to the ectosarc of Amoeba. 

 He states that "this living substance has a moderately high 

 viscosity," but he also says that it is a "quite concentrated gel" 

 (p. 155). Kite's use of the term gel is very broad. The nearest 

 approach to a firm gel condition of the protoplasm which I have 

 studied is that of the ectosarc of the ciliate Euplotes and the 

 quiescent protoplasm of bread mold, but even here the protoplasm 

 possesses considerable plasticity, and, although holding its shape 

 when freed, is of soft rather than solid consistency. 



Hyman credits Chambers with confirming these results of 

 Kite. This is not altogether true. To be sure, Chambers (5) 

 does say that "the external surface of the egg is a gel," and that 

 the surface layer of marine ova is directly comparable with the 

 "rigid ectoplasm" of Protozoa; but he nowhere states that normal 

 living protoplasm can be cut into small pieces. Quite the con- 

 trary, he calls attention to the fact that it is the protoplasmic 4t co- 

 agulate" (and a coagulum, as Hyman points out, is "incompatible 

 with life") that can be "cut into pieces which hold their shape"; 

 and adds that this is likely "to lead one to the erroneous conclu- 

 sion that the substance of a cell is usually a solid protoplasmic 

 gel." It is true, however, that the ectoplasm of Amoeba, when 

 not immediately concerned in pseudopodium formation, is of high 

 consistency, possessing, as Hyman says, many properties of solids, 

 such as great elasticity, extreme viscosity, and compressibility; 

 and this is sufficient to support the interesting theory (first advanced 

 by Montgomery, according to McClendon 20) that amoeboid 

 movement is "due to alterations of the colloidal state" (13) > 

 that is, it is a solation-gelation phenomenon. 















