In one of these short stories a man encounters his younger self on a Paris bus, follows him home and befriends him--not a child who reminds him of himself, mind you, but one who is reenacting his own childhood with complete precision. In another story a man reading a mystery gradually realizes that he himself is the victim in the story. There are also existential encounters with expressionless, reptilian creatures at the zoo. Cortazar is one of the great masters of Latin American short fiction, in every sense a peer of Borges and García Marquez.  (ARG20, $15.00)