The genie has returned yet again. (He already visited once back in 2007.) On a moonlit night, you walk on the beach, stub your toe against a bottle, which conveniently rolls against a rock and shatters. A genie emerges, eager to grant you one wish. You ask for a microbiological laboratory. The genie grants you that, and tells you that you can choose the topic of your research. However, he will let you use only one apparatus (besides incubators, Bunsen burners, inoculating loops, and a microscope). Which apparatus would you choose?