This image was acquired from
wikimedia. It was marked as Public Domain or CC0 and is free to use. To verify, go to the source and check the information there.
PSM Section of subsided floor at silchester. Section of subsided floor at Silchester archive org Popular Science Monthly Volume Author PDold Popular Science Monthly illustrations Compost Fertilization The Formation of Vegetable Mould through the Action of Worms
Page 2023 Free-images.com. All images are Public Domain