These holdings do not include all of Jones's correspondence in the field of biology, since he believed that collections, papers and letters about material from a given region should be deposited and preserved in that area. Other letters have been distributed among various individual correspondents, Boston Museum of Natural History, Society of Natural History of Wilmington, Delaware, and the U. S. National Museum. The Academy's collection contains letters from 166 authors who wrote a total of 934 letters plus 536 answers by Jones.