Marathon Fever. A rare condition observable only in Zamonian marathon runners. After some five hours of strenuous marathon running in the atmosphere prevailing in Zamonian mixed forests, with its extremely high oxygen content, the body temperature rises to 133 degrees Fahrenheit. In a person in a standing or recumbent position, this would be fatal; in someone engaged in running, it merely releases so-called bazirs into the blood, in other words, bacillumlike corpuscles productive by temporary delusions when they reach the brain. Far from putting marathon runners at a disadvantage, however, these help to desensitise them against their natural exhaustion and spur them to to further feats if athleticism. The said hallucinations are all of a pleasant nature, being associated with rapid progress. Those who have them tend to imagine that they are creatures noted for their speed, e.g. gazelles, cheetahs, or swallows.