INFLUENCE OF LOAD 57 



and in the last it was made 2000 mgrms. Successive records 

 were made, for purposes of comparison, on the same part 

 of the plate. The vertical lines under the diagram (fig. 26) 

 are time-marks, indicating intervals of one minute. It 

 will be seen that the height of the record, with a load of 

 100 mgrms. is the greatest of the three, being 41 mm. 

 The recovery was completed in this case after the expiration 



Fig. 26. — Effect of load ; the three records show responses under 

 varying loads of ioo, 500, and 2000 mgrms. 



of 9 minutes. The height of the second, under a load of 

 500 mgrms. is 28 mm., but recovery is nearly complete in 

 6.5 minutes. And, finally, with the load of 2000 mgrms. the 

 height is the least, being 13 mm., but the recovery is seen to 

 be completed in 5 minutes. Thus the effect of load in the 

 contractile response of the plant is shown to be strictly 

 parallel with its influence on the contractile response of 

 animal muscle. 



Work performed by the Plant 



The motile tissue of the plant, like that of the animal, 

 is capable of doing work during excitatory movement. 

 The influence of load on the height and period of response 



