The vast majority of the 33 volumes listed as "diaries" in the Raymond Pearl Papers might be better described as common-place books, though the collection includes at least six unbound volumes that might be accurately classified as diaries. Most of these entries pertain to various recreational European trips taken between 1905-1928. The 1905 diary includes numerous accounts of sightseeing in London, including visits to Kew Gardens (9/28), the Tower of London (9/30), and a theater, which Pearl compares to that of the United States (10/18). Pearl uses the next two journals, from 1916 and 1917 respectively, as field notebooks with miscellaneous accounts. These volumes will likely most interest scholars researching his biography and contributions to biology. A journal from 1918 includes a mix of typed and handwritten entries documenting a trip to Europe by steamship. Finally, the last two volumes might very well have been co-authored by both Raymond and Maud Dewitt Pearl. The first, a loosely bound journal bearing the dates "1924, 1927" appears to have been maintained by both Pearls. The second, dated 1928, appears to have been kept by Maud, especially given all of the third-person references to Raymond Pearl ("R.P."). Both "1924, 1927" and "1928" recount travels in England, France, and, to a lesser extent, Germany. These diaries, while quite limited in nature, may interest scholars researching Europe in the early-twentieth century, biology, and the history of science more broadly.