6o4 J- Frank Daniel 



and a prominent protrusion of the membranellar plates. Color — 

 a beautiful sea green — extruded. Body usually burst and rapid 

 destruction followed — the cilia remaining active as long as a par- 

 ticle of form remained. 



Acdijnatized Stentors. Stentors which had been acclimatized 

 in I per cent alcohol, upon subjection to y^^ NaOH turned rapidly 

 around and around for a few seconds. The body wall then gave 

 way and destruction followed with extreme rapidity. 



In a comparison of acclimatized and unacclimatized Stentors 

 two differences are noticed. Acclimatized animals show a greater 

 activity upon subjection to sodium hydroxide and this chemical acts 

 with greater rapidity upon the acclimatized forms. 



The most notable thing observed in the study of sodium hydrox- 

 ide was in relation to the pellicular membrane. If the pellicula 

 remained intact, life was often prolonged for a remarkable period 

 of time; if on the other hand the pellicular wall gave way, the cell 

 was dissolved with extreme rapidity — leaving only traces of pro- 

 toplasmic granules in the surrounding medium. 



Rapidity of death to those animals which have remained for a 

 brief period of time in alcohol has a possible explanation in the 

 fact, previously noted, that acclimatized Stentors, even in alcohol, 

 show an early distortion. A rupture of the pellicula in NaOH 

 means immediate death. If the process of acclimatization to 

 alcohol makes a rupture of this sort more probable, it would natur- 

 ally follow that if the organisms are first subject to a weak per- 

 centage of alcohol and then tested to a fatal dose of sodium hydrox- 

 ide they would meet an earlier death. This is in agreement with 

 what is seen in Experiment XVII. 



2 Effects upon Resistance 



In the following experiment acclimatized and unacclimatized 

 animals of both Stentor and Spirostomum were tested to see the 

 period of time that they could withstand an y^^ solution of so- 

 dium hydroxide: 



