These are the titles of the essays in

Animal Communication... Astonished Porcupine, An*... Beaver's Reason, A... Bird-Songs... Birds and Strings*... Colors of Fruits, The*... Crow, The*... Devious Paths... What Do Animals Know?... Do Animals Think and Reflect?... Factors in Animal Life... Gathered by The Way... Instinct*... Literary Treatment of Nature, The... Mimicry*... Nature with Closed Doors... Pinch of Salt, A... Reading The Book of Nature... Robin, The (1 of 2)*... Training of Wild Animals, The*... Ways of Nature... What Do Animals Know?... Wit of a Duck, The...