"Janson's rejection of all female artists has marred his reputation as an art historian, because his books paint only a half picture, omitting any art not done by men. His refusal to acknowledge women extends to the celebrated artist Idelle Weber. Sam Hunter, then curator at MoMA, introduced her to Janson, who admired Weber's work but stated that he did not include women painters in his books."
It is true, there is no mention in the book about any female artists.
(No wonder, then, about the way he died.)