Hisako is “about to give birth” (37) at the time of the cruise. Her unborn child has been tested for defects caused by radiation, as she lived near the site of the Hiroshima atomic bomb attack. The tests were clear but unable to detect that Hisako’s child Akiko would be born with a “fine, silky pelt like a fur seal’s” (37). This fur would help Akiko survive on the Galapagos island of Santa Rosalia. She represents a vast evolutionary step from her forebears—until the transition from Gokubi to Mandarax, which are both small, black plastic computers. Despite the similar appearances of the two, Mandarax is much more advanced. It provides medical diagnoses, historical information, and literary quotes with varying degrees of competency and accuracy.

The surviving generations on Santa Rosalia continued for some time with the traditions of marriage, which caused “many other sorts of heartbreak” (41). Eventually, they stopped. The narrator blames the problems of marriage on the oversized brains of previous generations of humans. Zenji and Hisako have problems in their marriage because Hisako is annoyed that one of Zenji’s workers programmed Mandarax to teach the art of flowering arranging, known as ikebana.