There was, until a year ago, a little and very grimylooking shop near Seven Dials, over which, in weather-worn yellow lettering, the name of ldquo;C. Cave, Naturalist and Dealer in Antiquities,rdquo; was inscribed. The contents of its window were curiously variegated. They comprised some elephant tusks and an imperfect set of chessmen, beads and weapons, a box of eyes, two skulls of tigers and one human, several moth-eaten stuffed monkeys (one holding a lamp), an oldfashioned cabinet, a flyblown ostrich egg or so, some fishing-tackle, and an extraordinarily dirty, empty glass fish-tank. There was also, at the moment the story begins, a mass of crystal, worked into the shape of an egg and brilliantly polished. And at that two people, who stood outside the window, were looking, one of them a tall, thin clergyman, the other a blackbearded young man of dusky complexion and unobtrusive costume .