connection between the neck 12 and the second end wall 26 it will be appreciated that a slight draft is provided in the side walls 20 and 22 and end walls 24 and 26 to facilitate removal of the lower part of the container from the mold during manufacture this in turn results in the slightly larger surface for top wall 18 so as to provide a firm seat for the bottom wall of another flask when one is stacked upon another the configuration of the flask and more particularly the canted neck 14 with its flat 38 and the ramp 36 provide several advantages it will be noted in the drawings that the width of the neck is larger than the height of the central portion 28 of the end wall 26 this extra wide neck along with the shape of the flask itself provides access to all four bottom corners 72 74 76 and 78 with a scraper the neck width will also permit a pipette to reach the four corners 74 76 80 and 82 of end wall 24 so as to remove medium from the bottom when the flask is placed on end as shown in fig4 furthermore the ramp angle minimizes the possibility of medium in the bottle flowing into the neck 12 also the canted neck and ramp prevent fluid retention when pouring medium into or out of the flask the.