a film of liquid, the cell material is usually fixed to the glass of the container, beingalternately exposed to air and to the nutrient medium. With this setup, a better reproductionof data on growth and development is generally observed than is the casewith shaker or agar cultures, especially in physiological or biochemical investigations.These “Steward tubes” (or T-tubes; Fig. 3.2, top) in our standard experimentsare supplied with three explants each. For many biochemical investigations, however,this is not enough cellular material. Based on the same principle for the productionof more material, so-called star flasks (or nipple flasks) were developed(Fig. 3.2, bottom). The inner volume of these vessels is 1,000 ml, usually 250 ml ofmedium is applied, and 100 explants are inoculated. Due to the nipples in the wallof the container during rotation of the shaft to which they are mounted, the cellularmaterial is fixed, and again as with T-tubes, alternate exposure to air and nutrient