The most common presenting complaint of DID is depression, with headaches being a common neurological symptom. Co-morbid disorders can include substance abuse, eating disorders, and anxiety. Things like posttraumatic stress disorder (PTSD) and personality disorders are introjected behaviors only.
Fourteen of them were the notebooks Darwin used on his shore excursions during the voyage of the Beagle (1831-1836). This is the first complete edition of these important notebooks, thirty years in the making. The notebooks were also published in 2009 as a book: Gordon Chancellor and John van Wyhe eds.
As a research vessel HMS Beagle may not have had the internet, but she did have an impressive state-of-the-art library of about 400 volumes. The library was housed in book cases in the poop cabin at the stern of the ship, which was also Darwin's cabin. Thus, Darwin lived and worked in the Beagle library for five years.