At the end of this chapter [1], Nick sees Gatsby on the lawn and is about to call to him but does not. What stops him? What does Gatsby's "trembling" suggest?

When the reader first sees Gatsby, he is reaching toward the green light ­ something that, by definition, he cannot grasp. In this scene, Fitzgerald wholly sacrifices realism in favor of drama and symbol: the green light stands for the as-yet-nameless object for which Gatsby is hopelessly striving.Gatsby is trembling towards the green light: he trembles for the illusion of Daisy.