1919, a pair of American pathologists220, Edward and Helen Krumbhaar, analyzed the effects of the Ypres bombing on the few men who had survived it. They found that the survivors had an unusual condition of the bone marrow. The normal blood-forming cells had dried up; the bone marrow, in a bizarre mimicry of the scorched and blasted battlefield, was markedly depleted. The men were anemic and needed transfusions of blood, often up to once a month. They were prone to infections. Their white cell counts often hovered persistently below normal.