The volume consists of an alphabetical index to Owen correspondence and brief abstracts. Includes 1981 letter (3 p.) from Gruber to British Museum regarding Owen calendar, key to locations of Owen correspondence, and an introductory essay (29 p.) by Gruber.

These are primarily scientific letters from Buckland. The subjects mentioned include Milne-Home's seismological investigations, Wheatstone's self-registering instruments, geology (glacial phenomena in Scotland, mineralogy, etc.), numerous references to fossils, and mentions of Mastodon bones and sloths.

Series I is a miscellaneous collection of letters concerning geology, geological exploration of Russia, entomology, glaciers, appointments in the British Museum, Geological Society of London business, Royal Geographical Society, references to David Livingstone, and zoology. Series II consists of letters written from America, to Murchison, discussing geology, natural history, and contemporary topics.

This collection contains correspondence on natural history, expecially mollusks, fishes, and birds, and on medicine and social affairs, with references to the British Museum of Natural History. Also included are a paper by Owen on dinosaurs and a synopsis of a course of lectures, 1857.

There is correspondence concerning geology, botany, natural history, natural selection, evolution, British science and scientists, and other scientific topics. Most of the letters are written by Lyell, with a very few items by others.