The story of Treves's patient, Joseph Carey Merrick (1862-1890), incorrected identified by Treves in these reminiscences as "John Merrick." The story was retold in The elephant man, Bernard Pomerance's 1977 play about Joseph Merrick's life, as well as David Lynch's 1980 film The Elephant man in which Treves was portrayed by Anthony Hopkins. 

"The exact cause of Merrick's deformities is unclear. The dominant theory throughout much of the 20th century was that Merrick suffered from neurofibromatosis type I. In 1986, a new theory emerged that he had Proteus syndrome. In 2001, it was proposed that Merrick had suffered from a combination of neurofibromatosis type I and Proteus syndrome. DNA tests conducted on his hair and bones have proven inconclusive," Wikipedia article on Joseph Merrick, accessed 7-28-2016.)

Digital facsimile from the Internet Archive at this link.