The second of five Histories of the Carnegie Institution of Washington describes the work of the Department of Terrestrial Magnetism. Since its beginning in 1904, the department has witnessed an astonishingly broad range of research projects, from terrestrial magnetism, ionospheric physics and geochemistry to biophysics and planetary science. Many contemporary photographs illustrate some of the remarkable expeditions and instruments developed in the pursuit of scientific understanding.

From humble beginnings as a small desert laboratory in Tucson, Arizona, at the beginning of the twentieth century, the Carnegie Institution's Department of Plant Biology has evolved into a thriving international center of plant molecular biology on the campus of Stanford University. This fourth in a series of five histories of the Carnegie Institution considers the beginnings of ecology, complexities of photosynthesis, great mid-century evolutionary synthesis and the start of the plant molecular revolution.

Founded in 1914, the Department of Embryology at the Carnegie Institution of Washington has made a great contribution to the biological understanding of embryos and their development. Although originally much of the research was carried out through experimental embryology, by the second half of the twentieth century, tissue and cell cultures were providing histological information about development, and biochemistry and molecular genetics dominated research. This is the final volume in a series of five histories of the Carnegie Institution of Washington.