At the end of chapter one, Pheoby and Janie are sitting on Janie's back porch and talking about Janie's experiences since she left home.
The last line of the chapter is impressionable, but also confusing:
"Time makes everything old so the kissing, young darkness became a monstropolous old thing while Janie talked" (7).
Hurston uses "kissin'" on the previous page: "come kiss and be kissed," and the rough translation is "come and talk to me." Hurston also invented the word monstropolous as a hyperbole and it is most likely an extension of the word monstrous. Once the literal phrasing is understood, the meaning and Hurston's intent behind this line is up for interpretation.
I think age is going to be part of a developing theme in this work, especially because it played such a large role in Hurston's life; she frequently lied about her own age, and she was buried with an unmarked grave. To this day, her actual age at the time of her death is unknown. Hurston refers to age and youth in the neighbors' descriptions of Janie and their gossip about what is and what isn't appropriate for a woman "way past forty" (3).
In this last line particularly, she's saying that even as the women talked for that brief spanse of time, the "young darkness" grew old around them, emphasizing an importance on time and the fleetingness of life.
Hurston could also be referring to the time of day as Janie talked; the darkness growing old meaning it was getting late. I'm not really sure. I think it could be both. By leaving the audience with this line at the end of chapter one, Hurston sets a distinct tone for the novel and foreshadows future conflict about fading youth and social expectations reflective of her personal experiences.