Complex sentence: Another recurring joke is the use of fictional apparatus and materials used in the experiments--items such as the "Besselheim plate" pokes fun at real lab equipment, often named after their designers (e.g. Petri dish, Erlenmeyer flask).
Split into simpler sentences: Another recurring joke is the use of fictional apparatus and materials used in the experiments. Invented items such as the "Besselheim plate" have names akin to real lab equipment named after their designers (e.g. Petri dish, Erlenmeyer flask).