Former Gov. George C. Wallace was recovering quickly from a potentially life-threatening bacterial blood infection, hospital officials said. Wallace, 79, was still in critical condition and his vital signs were stable Friday, said Victoria Jones, spokeswoman for Jackson Hospital. She said the four-term governor had shown "marked improvement" since arriving at the hospital suffering from septic shock and breathing difficulties. This is the third time in four months that Wallace has been hospitalized after suffering respiratory problems.