Effect of Chcin/cals on Growth Z22 



Adult Paramecia are more resistant than young specimens to 

 the stronger solutions. 



Effects of Alcohol on Growth 



Introductory. So much has been written in the last few years, 

 and such diverse results reached on the effect of alcohol upon 

 higher animals that it will be interesting to study the effects of 

 alcohol upon growth in single cells. Calkins and Lieb,'' in 1902, 

 showed that "alcohol had no effect upon Paramecium taken in 

 too weak doses and too powerful an effect when taken in over 

 strong doses," also "when a medium dose was given, i.e., one part 

 of alcohol in 2,500 of hay infusion, the effect is a continued stim- 

 ulus which sustains the high rate of division even during periods 

 of depression of the control series." 



Woodruff,'" in 1908, found that alcohol increased the rate of 

 division at certain periods in the life cycle of Paramecium and 

 decreased it at others. He also found that the increased rate of 

 division was not lasting, but that doubling the amount of alcohol 

 again caused a rapid cell division for a limited period. 



It will be of value, then, to see what effect different amounts of 

 alcohol will have upon growing Paramecia, and whether minute 

 quantities will cause increased size or increased rate of division. 



Effect of Alcohol 0)1 Groiuing Paramecia 

 Groivth 111 j per cent solution of alcohol in hay infusion. Young 

 Paraniecia just after separation were used, in the way described 

 on page 491. Some growth took place in a 5 per cent solution of 

 alcohol in hay infusion, but the animals did not grow so fast at any 

 time as the controls." All those in the alcohol were dead at the 

 end of 5 hours (see table XXXII). 



Growth in 7 per cent alcohol. A certain amount of growth took 

 place in 3 per cent alcohol, but the specimens in the alcohol did 



* Loc. cit., page •^64. 



'" Loc. cit., page 85. 



" The i^lides contaming the alcohol cultures of Paramecia were kept in a separate chamber from the 

 the controls. In the moist chamber containing the alcohol cultures, the bottom was covered bv a ";% 

 solution of alcohol and in this way loss of alcohol by evaporation from the culture drops was prevented. 

 The control cultures were of course kept in water vapor alone. In the other strengths of alcohol studied, 

 similar precautions were taken. 



