City series

Story, first published: Astounding Science Fiction, Dec. 1947

"Aesop," the seventh tale, leaps ahead another five thousand years. Jenkins is celebrating his 7000th birthday, and the dogs have given him the present of a new body. Technology has been left to the wild robots. The animals, with their robot companions, have built a civilized society under the guidance of the dogs. Killing is absolutely forbidden, causing a bad problem of over-population. The wild robots are building starships, and the dogs have probed into time travel in an effort to siphon off the growing numbers. A remnant of humanity exists, known under the generic term of "websters," the descendant of Jon's son and some others caught outside when Geneva was cut off.
Jenkins tries to keep the memories of humanity's achievements and the glory of the Websters alive. However, the old human way of thought is threatening to come back. One of the websters, Peter, has killed a robin with his bow and arrow. Jenkins must solve the "bow-and-arrow" problem before killing spreads again. He seeks out the mutants for help, but finds they have departed for other worlds.
The dogs are seeking ways to travel to the alternate worlds of the Cobblies to relieve the population pressure. The murderer Peter and the wolf Lupus meet one of the Cobblies. When the Cobbly kills Lupus, Peter's psychic projection of hate frightens the Cobbly back to his own world. Jenkins arrives on the scene in time to read the incantation from the Cobbly's frantic mind. Jenkins now knows what he must do. At the webster picnic, Jenkins recites the incantation, transporting himself and the whole human race into the Cobbly world, finally eradicating the human species from Earth.

Ewald, Robert J.: When the Fires Burn High and the Wind is from the North, p.45-46