What's this painting?

It’s a well-known painting, I think. It’s definitely Cubist. It shows two women, one from behind the horizon and one in front, putting a stick vertically into a half of a gourd. I know that an interpretation of the painting is that in putting these together, they are creating the world. Does anyone know the name of the painter and the painting? Please help – this is really bugging me because I stared at a giant poster of this painting for a year every time I took a shit, and I should really know this.