240 



The Structure of Protoplasm 



Early in this experimental work, the plasmodium was recognized 

 as polyrhythmic. Each reservoir in the model shown in Figure 18 

 has only a single frequency of rhythm, whereas, the motive force 

 generated in the protoplasm lying in one compartment will be of a 

 number of different frequencies existing simultaneously. At this 

 point, the analogy drawn between protoplasm and model ceases to 

 hold. In order to make the analogy hold for the polyrhythmic fea- 



FiG. 19. 



ture of a plasmodium, a second model must be constructed. Such a 

 model is shown in Figure 19. Here we have a double chamber con- 

 taining a two-reservoir system connected by a single tube like that 

 in Figure 18, but here each reservoir has an arbitrary number of 

 pulsating pistons of various sizes. 



Let us suppose that a balance-pressure is applied to compartment 

 B, so as to keep the water in the connecting tube at a standstill. 

 When all the cranks of these pistons rotate slowly with the same 

 angular velocity, the levels of the two reservoirs undergo simple 

 harmonic motion, since any number of simple harmonic motions of 

 the same frequency is always combined, regardless of amplitudes and 

 phases, into one simple harmonic motion of the same frequency. If, 

 however, some of the cranks turn with different angular velocities, 

 the two levels no longer show simple harmonic motion. The differ- 

 ence, h, between the two levels to which the pulsation of each small 



