A series of natural-history sketches presents the early lives of various wild mammals, portraying how each species is born, nurtured, learns to feed, move, and protect itself in its habitat. Each chapter focuses on a different animal—pouch-carrying opossums, sea-cows and whales, hoofed deer, gnawers like beavers and squirrels, burrowing moles, and carnivores such as foxes and wolves—describing nesting, feeding, locomotion, building or digging, seasonal habits like hibernation, and parental care. Simple anecdotes and illustrations emphasize diversity of form and behavior, stages of growth, and the practical skills young animals must acquire to survive in forests, plains, mountains, and waters.