74 RESEARCHES ON IRRITABILITY OF PLANTS 



on the organ before complete protoplasmic recovery has 

 had time to take place, during the usual resting-interval 

 of 15 minutes. The consequence of this is the diminished 



Fig. 35. — Record showing growing fatigue in Mimosa. 



excitatory effect exhibited in the second response. As the 

 excitation in this case was relatively slight, the recovery 

 was very much more complete than in the first. The 



Fig. 36. — Periodic fatigue ; alternate responses here tend 

 to become uniform. 



third response therefore was large, but not so large as the 

 first, when the organ was fresh. This excitation, however, 

 being less than the first, recovery is also somewhat more 



