ACTION OF ALKALIES ON PLAXARIA. 



337 



and determine the effect of alkalinity on the time of death. Lack 

 of oxygen was one condition that seemed suitable for a test. A 

 petri dish was divided into three compartments by two paraffin 

 walls. A powder made by grinding up pyrogallic acid and sodium 



10 



4 5 6 7 8 g 10 ii 12' 

 FIG. 3. Graph of disintegration gradient of worms exposed to NaOH solution 

 and tested in alkaline alcohol (broken line) and worms not exposed to alkali and 

 tested in neutral alcohol (heavy line). Alcohol used was 4 per cent. Hours on 

 the abscissa and stages in disintegration on the ordinate. (See text for stages.) 



3 4 567 8 9 fo }j T? 

 FIG. 4. Graph of disintegration gradient of worms exposed to NaOH solution 

 and tested in alkaline chloretone (broken line) and worms not exposed to alkali 

 and tested in neutral chloretone (heavy line). Chloretone used was o.i per cent. 

 Hours on the abscissa and stages in disintegration on the ordinate. (See text 

 for stages.) 



hydroxide was placed in the center between the two paraffin walls. 

 (. hi one side of this were placed ten to twentv worms in ordinary 

 water (pH 8.0) ; and on the opposite side in the third compart- 

 ment, an equal number of worms of the same size and physiological 



