26o 



CHARLES E. BILLS. 



isms in plain spring water, but that under like conditions, except 

 that 3.0 per cent, ethyl alcohol was present, the sunlight inacti- 

 vated 42 per cent. The experiments were repeated in diffuse 

 daylight, and not one individual was inactivated in the absence 

 of alcohol, while with 3.0 per cent, alcohol 8.9 per cent, were 

 affected a figure not significantly different from the values 

 got in the temperature experiments which were made in darkness. 



TABLE V. 



SHOWING THE INFLUENCE OF LIGHT ON THE SUSCEPTIBILITY OF PARAMECIA TO 



ETHYL ALCOHOL. 



The Combined Effect of Preliminary Aeration and Agitation 

 of a Paraniecium Culture on its Subsequent Susceptibility to an 

 Alcohol. Aeration was effected by agitating for two minutes 

 some paramecia of Clone 10 in 1.6 per cent, of i-propyl alcohol. 

 This alcohol was chosen because of the fine froth produced 

 when cultures containing it are violently shaken. The results 

 presented in Table VI. show that the aerated paramecia are 

 decidedly less susceptible than normal controls. Of the agitated 

 organisms 17 per cent, were narcotized, whereas 32 per cent, 

 were narcotized in the non-aerated control culture. 



TABLE VI. 



SHOWING THE INFLUENCE OF AERATION AND AGITATION ON THE SUSCEPTIBILITY 

 OF PARAMECIA TO 1.6 PER CENT. J'-PROPYL ALCOHOL. 



