In "The Edible Woman" Duncan eats pumpkin seeds in the movie theatre, which Marian thinks are "like some primitive signal" which "she could not interpret." Explain.
I'm not really sure what you are needing here, as this is not a question, but I will take a stab at it. In the chapter of The Edible Woman to which you are referring, Marian has gone to a movie alone because her roommate has plans to seduce the man she wants to impregnate her. Marian is slouched down in a seat in a kind of Zen acceptance, and she hears little crunches. It is Duncan, the man she keeps running into whom she originally met while conducting a survey for her job. This is after Marian has accepted her boyfriend Peter's proposal of marriage, and the book has switched from first person to third as if Marian has already lost herself. She and Duncan (and at this point she does not even know his name) do not even speak or acknowledge one another in the theater, but he whispers to her on the way out that he has been eating pumpkin seeds. Briefly she thinks she has hallucinted the entire encounter, but she goes to his seat and looks at the pile of shells. They indicate that at least she isn't totally crazy and that he was there; the pile of shells is proof. She leaves the theater without seeing him again and returns home as if nothing had happened, knowing somehow that she will encounter him again.