226 



The Structure of Protoplasm 



polarity, for which the displacement of the whole plasmodium is 

 responsible, changes its intensity spontaneously. It may tentatively 

 be assumed that polarity and rhythm are independent variables. 

 This is a permissible assumption until the concrete meanings of 

 polarity and rhythm are elucidated on a physical or chemical basis. 



UJ 



cr 



D 



(^ „ 

 (/) cr 

 LJ ^ 



cr 



Q. 



I 

 UJ 



U 



< 



CD 



16 



14 



12 



10 



8 



6 



4 



2 







-2 



-4 



-6 



-8 



-10 



-12 



-14 



TIME IN MINUTES 



Fig. 12. 



Although the true axes, or polarity-lines, are not shown in the above 

 figures, except in Figures 10, 12, and 13, nevertheless, it is possible to 

 find them in all cases with a limited degree of accuracy. 



VIII. CHARACTER OF PROTOPLASMIC RHYTHM 



We are now confronted with the fundamental problem of the 

 character of the rhythm operated in the protoplasmic system. If the 

 spontaneous increase and decrease in amplitude of the waves under 

 the same external conditions are regarded as due to a physiological 

 disturbance or to "fatigue" of the protoplasm, the question naturally 

 arises, just what is the physiological disturbance; what is fatigue 

 of protoplasm. A further question is the cause of the repeated 



