 Nor is the egg passive: adhesive molecules on its surface play a crucial role in overcoming the sperm’s tendency to pry itself away (Martin 1996: 108). Martin argues that scientists have been slow to discover these facts, partly due to the metaphors they employed; and that even as they have learned these facts they have been slow to update their metaphors. Gendered stereotypes, Martin suggests, can impair our understanding of reproduction—by leading scientists to employ misleading metaphors that conceal the truth. The use of gendered stereotypes in scientific imagery can also help to perpetuate damaging stereotypes, for example by reinforcing the tendency to see females as passive. Martin’s account has, however, been challenged by Paul Gross (1998), who argues that scientists were not nearly so slow to these discoveries as Martin claimed. If Gross is right, then the problematic metaphors did not affect scientists’ work in the ways suggested by Martin (though they do seem to have affected popular writing on the subject.)