PROTEIN UPTAKE IN AMOEBAE 619 



think that the movement of carbon and carmine particles apparently on the 

 membrane does not indicate beyond doubt, the movement of the membrane. 



Allen : If you place a micro-needle through an amoeba, carbon particles 

 attached to the membrane behind the needle will move around the needle. On the 

 other hand, when you put an oil droplet on the surface, it apparently makes a firm 

 contact causing the membrane to adhere to the ectoplasmic tube at this point, in 

 the same way that the membrane adheres to the ectoplasm tube on the bottom of a 

 pseudopod. Thus I still think that the membrane slides forward over newly form- 

 ing ectoplasmic tubes. 



Davis : I think it is fair to say that the fact that papers on pinocytosis were 

 placed in different parts of this Symposium is perhaps an indication that we arc 

 not yet quite clear on the function of pinocytosis in the cell. 



