Hypothetical types of biochemistry in the late 1960s, these machines are often classed as computers (or computer-guided robots) and filed under "silicon-based life", even though the silicon backing matrix of these processors is not nearly as fundamental to their operation as carbon is for "wet life". Arsenic, which is chemically similar to phosphorus, while poisonous for most life forms on Earth, is incorporated into the biochemistry of some organisms. Some marine algae incorporate arsenic into complex organic molecules such as arsenosugars and arsenobetaines. Fungi and bacteria can produce volatile methylated arsenic compounds. Arsenate reduction and arsenite oxidation have been observed in microbes ("Chrysiogenes arsenatis").
Gasteroid fungi described by Linnaeus in his original "Species Plantarum" of 1753, but the first critical treatment of the group was by Christiaan Hendrik Persoon in his "Synopsis methodica fungorum" of 1801. Until 1981, this book was the starting point for the naming of Gasteromycetes under the "International Code of Nomenclature for algae, fungi, and plants". Although the starting point was subsequently put back to 1753, names of gasteroid fungi used in Persoon's book are still sanctioned and cannot be replaced by earlier names. Elias Magnus Fries introduced the name Gasteromycetes for a class of fungi in his "Systema Mycologicum" of 1821,