They Walk the Earth

by Seymour Simon

Published 28 September 1999
Describes the movement and migration of mammals and amphibians over varying conditions of land, covering such species as lemmings, elephants, caribou, and frogs.

They Swim the Seas

by Seymour Simon

Published 15 September 1998
Describes the migration of marine animals and plants as they journey through rivers, seas, and oceans.