This 1975 image depicts a laboratory apparatus still life that included an air-tight, yellow-topped GasPak™ jar, containing tubes and Petri dish culture plates, and a pressure monitoring gauge, which had been connected to the jar using black rubber tubing. The GasPak™ jar is used to create an anaerobic environment, which means an atmosphere free of oxygen, in which organisms that thrive under such conditions may be cultivated in the laboratory. Clostridium spp. bacteria, which includes Cl. botulinum, i.e., the cause of botulism, are examples of obligate anaerobic organisms, meaning that they cannot thrive in an environment containing molecular oxygen. For another view of a GasPak™ jar, see PHIL 3595.