From the point of view of an inhabitant of the Old World, marsupials are exceedingly odd. But oddity is not the same as randomness. Kangaroos and wallabies may lack verisimilitude; but their improbability repeats itself and obeys recognizable laws. The same is true of the psychological creatures inhabiting the remoter regions of our minds. The experiences encountered under the influence of mescalin or deep hypnosis are very strange; but they are strange with a certain regularity, strange according to a pattern.

