Page 6 Lithotomy: Wellcome Collection; Charles Brown-Séquard:Bridgeman Images; Adolf Butenandt: ? SZ Photo/Scherl/Bridgeman Images.
Page 7 Frederick Banting: Hulton Archive/Getty Images; Case VI insulin patient: Wellcome Images.
Page 8 Gray's Anatomy: ? King's College London/Mary Evans Picture Library; Charles Byrne skeleton: ? Ken Welsh/Bridgeman Images; dissecting room at St George's Hospital with Henry Gray: Wellcome Collection.