The text discusses geological theories regarding the distribution of dense and less dense materials in the Earth's crust. It suggests that the dense Sima (a type of crustal material) was exposed in the ancient Pacific, while the lighter salic continents have been displaced, leading to the current arrangement of oceans and continents. The author argues that the Pacific and continents are permanent, while the Atlantic and Indian oceans are younger, with their floors composed of Sima that has risen to the surface due to continental displacement. This explanation resolves contradictions in the concept of permanence in geological formations. The text also reviews a geological work that presents paleogeographic data, including sedimentary formations, estimates of geological time, and examples of paleogeographic maps. It praises the work for its comprehensive summary of stratigraphy and paleontology, along with its rich illustrations. The book is aimed at amateur botanists and nature lovers, offering a clear evolutionary account of plant life, with detailed descriptions of field characters and illustrations. The book includes chapters on various plant groups, with a general glossary and index. The text then lists articles from the Proceedings of the National Academy of Sciences, covering topics such as X-ray absorption, plant pathology, sea-anemone locomotion, coral reefs, and the geological role of phosphorus. It also includes a discussion on the origin of certain Fiji atolls and the influence of Silurian-Devonian climates on the rise of air-breathing vertebrates. The text concludes with a study on the density of radio-lead from Norwegian cleveite.The text discusses geological theories regarding the distribution of dense and less dense materials in the Earth's crust. It suggests that the dense Sima (a type of crustal material) was exposed in the ancient Pacific, while the lighter salic continents have been displaced, leading to the current arrangement of oceans and continents. The author argues that the Pacific and continents are permanent, while the Atlantic and Indian oceans are younger, with their floors composed of Sima that has risen to the surface due to continental displacement. This explanation resolves contradictions in the concept of permanence in geological formations. The text also reviews a geological work that presents paleogeographic data, including sedimentary formations, estimates of geological time, and examples of paleogeographic maps. It praises the work for its comprehensive summary of stratigraphy and paleontology, along with its rich illustrations. The book is aimed at amateur botanists and nature lovers, offering a clear evolutionary account of plant life, with detailed descriptions of field characters and illustrations. The book includes chapters on various plant groups, with a general glossary and index. The text then lists articles from the Proceedings of the National Academy of Sciences, covering topics such as X-ray absorption, plant pathology, sea-anemone locomotion, coral reefs, and the geological role of phosphorus. It also includes a discussion on the origin of certain Fiji atolls and the influence of Silurian-Devonian climates on the rise of air-breathing vertebrates. The text concludes with a study on the density of radio-lead from Norwegian cleveite.