152 



The Structure of Protoplasm 



vertently had been included with the Amoeba in the pressure 

 chamber, continued without any sign of abatement while the pres- 

 sure was maintained at 7,000 Ibs./in.- for a period of about half an 

 hour. Also, Marsland and Rugh ('40) could observe no change in 



Fig. 10. (From Pease, '39, p. 137.) A single complete record of changes in the 

 ciliary rate with rapid pressure changes of 5,000 Ibs./in.^ 



the motility of sperm (Rana pipiens) during a compression period 

 of 3 hours at 8,000 Ibs./in.^ 



V. GENERAL DISCUSSION 

 A. NATURE OF THE PRESSURE EFFECT ON GEL STRUCTURE 



One important question which must be raised is whether the 

 influence of pressure on protoplasmic gel systems is a direct action 

 upon the sol ^ gel equilibrium itself, or whether the direct action 

 may be upon some other of the metabolic equilibria in the cell, 

 which in turn may mediate the effect upon the gel system. 



At the present time it would seem that the weight of evidence 

 favors the direct action view. Freundlich ('37) , on the basis of work 

 by Heyman ('35 and '36), points out that gel equilibria fall into 

 three categories, according to volume changes'^^ which accompany 

 the setting of the gel. In the first type, which is exemplified by 



