Erratum
In the report "Bronchoconstrictor effects of leukotriene C in humans" by J. W. Weiss et al. (9 Apr., p. 196), the second sentence of the abstract should have read: "Leukotriene C was 600 to 9500 times more potent than histamine on a molar basis in producing an equivalent decrement in the maximum expiratory flow rate at 30 percent of vital capacity above residual volume."