Membrane supply and food vacuole formation in Paramecium primaurelia

In Paramecium primaurelia food vacuole formation depends on membrane material supply. By using different solid particle concentrations in unbacterized culture medium it is shown that a given amount of membrane material is available for food vacuole formation. This membrane amount is utilized more rapidly if the concentration of particles is higher (where the size of food vacuoles is larger), than for a lower concentration (where the size of food vacuoles is smaller). After the utilization of the membrane which was available for the cell, a decrease of the number of food vacuoles occurs. Furthermore, the rate of food ingestion decreases when starved cells were pressed continuously to form food vacuoles, because of particles suspended in the culture medium.