INHIBITION OK LOCOMOTION IN PARAMECIUM. 



These may be inactivated, incoordinated or cytolyzed. If the nar- 

 cotized animals are removed to a normal medium, those of them 

 which are not too severely affected slowly recover. Recovery is 

 indicated by a beginning of locomotion accompanying the reap- 

 pearance of the body cilia. Whether these are actually regenerated 

 or merely reextended and stiffened for swimming has not been 

 determined. 



TABLE I. 



SHOWING THE OPTIMUM CONCENTRATIONS OF PROPYL ALCOHOL REQUIRED TO 



INHIBIT LOCOMOTION IN EIGHT PURE LINES OF Paramecium. 

 The percentages by volume are estimated from the conversion equivalents 

 for ethyl alcohol. 



It appears that the permissible variation from the optimum nar- 

 cotizing concentration is greater with iso and normal propyl alco- 

 hols than with any of the quieting agents heretofore employed. 

 With different cultures, however, the narcotizing concentration 

 varies considerably, as the results presented in Table I. indicate. 

 This table gives the optimum concentrations of the two propyl 

 alcohols when used on various typical pure line cultures of Para- 

 mecium caudatuni and Paramecium aurelia. It should be noted 

 that the former species narcotizes more satisfactorily than the lat- 

 ter, and that wild cultures, or mixed cultures of pure lines, are 

 more satisfactory than single pure lines of either species, since 

 among the varied specimens of the mixed "populations" a con- 

 siderable number which will narcotize properly can be much more 

 readily found than in the more uniform specimens of the pure 

 stocks. 



