Allie’s Mitt: Allie’s Mitt represents Holden’s reluctance to get over his brother’s death, while at the same time allowing him to preserve a tangible link to the innocence of childhood, both his own, and Allie’s.
The Museum of Natural History: The Museum, and Holden’s interactions with it, represent his obsession/ideal of preserving things, chief among them the innocence of childhood he sees as exemplified in Phoebe and Allie. The museum never changes, even as Holden does, which he finds comforting, a stationary piece of security in the turbulent waters of his developing adolescence.
Holden’s Hunting Hat: Holden’s hat is the ultimate security blanket. He is aware of how unique, and therefore noticeable, it is, and he is careful not to wear it when he is around people he knows. [The fact that the hat is red is also significant, as it is red like Phoebe and Allie’s hair, so Holden could possibly wear it to feel a closer connection to his siblings.] The hat also raises the question of what exactly Holden is hunting/searching for. Possible “targets” include his feelings over Allie’s death, and his search for religion and what it means for him to be an adult, and how he might go about completing that journey. Also, does giving his hat to Phoebe signify that he is ready to become an adult, and realizes that now phoebe needs the same protection and safety blanket that he once used?
The Ducks/Pond: The Ducks, and the Pond in Central park, represent the cyclical nature of things and also the impermanence of much of life. The ducks leave every year, but they eventually return, completing the cycle metaphor while reinforcing that few things last forever. They also have a destination with each flight, they are returning home, which is also, in a way, Holden’s ultimate goal. The Pond similarly represents the impermanence of circumstance, as it is partially frozen when Holden sees it. In the fact that it is partially solid, partially liquid, it represents Holden’s transition from boy to man, as he is neither one nor the other, but in the process of shifting between the two.
The Carrousel/Gold Ring: The Carrousel represents the cyclical nature of life, both in that it’s a circle, and in the fact that it is almost constantly in motion, but in shifts. This mirrors the development we undergo as part of life. [Just as Holden once rode the carrousel, and Phoebe currently does, one day Holden’s children will ride, and he will be there to potentially catch them, as he contemplates while Phoebe is riding.] The Gold Ring, similarly, represents both the hope that there is always something to strive for, as well as the risks necessary to undergo the transformation from boy to man, teen to young adult, etc. There is nothing to gain without a risk or some personal growth, all of which is symbolized by the Ring, almost out of reach, but still potentially attainable if we are willing to reach for it. Possibly plays into the symbolism of winter as adulthood, as Phoebe mentions that she didn’t think the carousel was open in winter.