Task: Question Answering
Input (English): Passage: The Aurora arrived at Cape Denison on 13 January 1913. When Mawson's party failed to return, Davis sailed her east along the coast as far as the Mertz Glacier tongue, searching for the party. Finding no sign and reaching the end of the navigable ice-free water, they returned to Cape Denison. The oncoming winter concerned Davis, and on 8 February—just hours before Mawson's return to the hut—the ship departed Commonwealth Bay, leaving six men behind as a relief party. Upon Mawson's return, the Aurora was recalled by wireless radio, but powerful katabatic winds sweeping down from the plateau prevented the ship's boat from reaching the shore to collect the men.The Aurora returned to Cape Denison the following summer, in mid-December, to take the men home. The delay may have saved Mawson's life; he later told Phillip Law, then-director of Australian National Antarctic Research Expeditions (ANARE), that he did not believe he could have survived the sea journey so soon after his ordeal.The cause of Mawson and Mertz's illnesses remains in part a mystery. At the time, McLean—the expedition's chief surgeon and one of the men who had remained at Cape Denison—attributed their sickness to colitis; Mawson wrote in The Home of the Blizzard, his official account of the expedition, that Mertz died of fever and appendicitis. A 1969 study by Sir John Cleland and R. V. Southcott of the University of Adelaide concluded that the symptoms Mawson described—hair, skin and weight loss, depression, dysentery and persistent skin infections—indicated the men had suffered hypervitaminosis A, an excessive intake of vitamin A. This is found in unusually high quantities in the livers of Greenland Huskies, of which both Mertz and Mawson consumed large amounts.While hypervitaminosis A is the generally accepted medical diagnosis for Mertz's death and Mawson's illness, the theory has its detractors. Law believed it was "completely unproven ... The symptoms that were described are exactly the ones you get from cold exposure. You don't have to predicate a theory of this sort to explain the soles coming off your feet." A 2005 article in The Medical Journal of Australia by Denise Carrington-Smith suggested it may have been "the psychological stresses related to the death of a close friend and the deaths of the dogs he had cared for", and a switch from a predominately vegetarian diet that killed Mertz, not hypervitaminosis A. 
Question: What were the last names of the men Cleland and Southcott indicated had suffered hypervitaminosis A?
Output (English): Mertz.