INHIBITION OF LOCOMOTION IN PARAMECIUM. 13 



seen. The activities of the undulating membrane, in directing the 

 passage of ' food" particles (Chinese ink) to the vortex at the 

 distal end of the gullet, and in returning unaccepted particles to the 

 peristome, are rendered easy of observation by the quieting action 

 of propyl alcohol. It may be, however, that the normal process 

 of food acceptance is modified by the drug when sufficient of the 

 latter is employed to effect a complete narcotization. 



SUMMARY. 



1. Normal and iso propyl alcohols, in concentrations around two 

 and three per cent., respectively, are superior narcotizing agents 

 for Paramecium. 



2. In narcotized paramecia it is possible to observe with con- 

 venience the structures and activities characteristic of the organism. 



3. The cyclosis is not a uniform flow, but is subject to waves 

 of acceleration. 



4. The oesophagus is a much more extensive structure than is 

 generally represented in the literature. 



