A tumbler containing a piece of potato. It is covered with cotton. This is used to grow bacteria.
Keywordsbacteria, tumbler, how are bacteria grown, is a tumbler used to grow bacteria, how is bacteria grown, growing bacteria, how to grow bacteria
Hilgard, E. W. and W. J. V. Osterhout Agriculture for Schools of the Pacific Slope (New York, NY: The MacMillian Company, 1910)