210 The Structure of Protoplasm 



5-second sound signal was given by an apparatus operated by a 

 synchronous motor whose speed was governed by A.C. cycle con- 

 stancy. By plotting a series of these succeeding values as ordinates 

 against time as abscissas, undulating curves were obtained which 

 faithfully portray the distinguishing features of the changes which 

 the motive force undergoes in accordance with the autonomic 

 scheme of the protoplasm. The graphs thus obtained, which shall be 

 referred to as "dynamoplasmogram," give a complete pattern of the 

 rhythm in protoplasmic activity. All the characteristics of rhythm 

 such as wave form, frequency, polarity, and amplitude are portrayed 

 by graphical representation. 



So striking and impressive is the rhythmic flow of the protoplasm, 

 that one is inclined to view the streaming as the significant thing, 

 when actually it is only the visible end-effect of the motive force. 

 The speed of flow is a function not only of the motive force, but also 

 of various factors which are not kept constant during the rhythmic 

 flow, such as thickness of the strand, viscosity,'^ etc. 



Holding protoplasm quiet artificially is a method which has 

 decided advantages. By such means, the motive force can be meas- 

 ured directly under statical conditions, thus eliminating numerous 

 factors which would possibly exert a disturbing influence. It was 

 possible, through the development of special techniques, to measure 

 continuously rates of flow and volume of protoplasm transported. 

 When these values are plotted against time, they yield rhythmic 

 wave patterns comparable to the dynamoplasmograms. However, 

 the dynamoplasmograms will be considered exclusively as a standard 

 of rhythm in the present paper, because the motive force when thus 

 measured is purer in respect to the rhythmic functioning of proto- 

 plasm than any other observable phenomenon. 



In order to understand a dynamoplasmogram, it is necessary to 

 remember that the protoplasm is being opposed and kept at a stand- 

 still. In other words, what one observes is quiet, but what one 

 measures is a motive force which still functions, i. e., the rhythm 

 continues. The value of the balance-pressure at any point in the 

 time scheme represents the motive force responsible for the flow 

 which would have taken place were the balance-pressure removed at 

 that moment. In virtue of the high sensibility of protoplasmic mobil- 



' Viscosity may not remain constant under different rates of shear (velocity 

 gradient) during the normal rhythmic flow, since protoplasm is thought to be 

 non-Newtonian in nature (Pfeiffer, 1936, 1937). 



