IRRITABILITY : INFLUENCE OF LIGHT 215 



movement because of the contrary influence of other factors 

 under abnormal circumstances. 



Jennings in his description of the movements of the Flagel- 

 lates states that these organisms have two movements, one 

 the normal, and the other, which is brought into play only 

 when the organism is abnormally placed. The idea seems 

 fanciful. 



