It's probably more a case of my having forgotten, but I don't recall from that book much description of the mental breakdown of another member of the expedition - Sidney Jefferyes. He was one of the six who had to stay in the hut for another year after missing the boat.
His story is briefly told in ABC News today, and here are some highlights:
There appeared to be no indication of Jeffryes' mental health problems until July 1913 when he got into several fights with his colleague Cecil Madigan, he stopped washing himself, and began collecting bottles of his own urine.
The expedition's medical officer wrote that Jeffryes was hallucinating and suffering from "delusive insanity".
Tensions grew further when another crew member found that Jeffryes had been telling Macquarie Island, via morse code, that he was the only sane member left on the expedition.
Mawson intervened, stating "Censor all messages Jeffryes insane" via morse, and removed him from most active duties.
In a letter declaring his sanity to his sister, Jeffryes wrote: "I am to be done to death by a jury of six murderers who are trying to prove me insane originating possibly from the jealousy of the six of them".
When the Aurora finally returned and took the men to Adelaide in early 1914, the ship's Second Officer Percy Gray wrote that "poor old Jeffryes, the wireless man, is beginning to go dotty again".
"The fellows were at the braces, they all rushed from one to the other and Jeffryes, whose cabin is on deck, thought they were coming to put him in his coffin, and leapt out of his bunk and barricaded the door."
"Poor chap, I am very sorry for him."Despite this, he was allowed to get on a train by himself, apparently to travel back to his home town of Toowoomba, and instead was later found wandering the Victorian countryside (naked, says one article - but another refers to having money in his pocket). It seems he spent the rest of his life in insane asylums, at least one of which was possibly colder in winter than the hut in Antarctica.
What a sad life!
Anyway, I see that Mawson, when asked about Jeffryes making his way home unaccompanied, claimed that he thought he had recovered fully during the ocean voyage back, and the doctor who had shared his cabin thought so too. Yet, you have that ship's officer in the above quote saying the opposite. Perhaps this goes towards supporting the "Mawson was actually a jerk" theory which, as I noted in my 2011 post, seemed to be something of a relatively novel theme in Heather Rossiter's book. (And got further backing in a, ahem, somewhat controversial revisionist biography in 2013 which speculated that he may have eaten one of his co-expeditioners to stay alive!)