The Mummies

On the other hand, you could argue that Holden draws a distinction between death and disappearing, and that's why he's so into the mummies. He explains the process of mummification to two younger boys with enthusiasm; mummies are blatantly representative of death, but rather than get depressed by the obvious morbidity of the subject matter, Holden is fascinated by the thought that some things stay as they are. The mummies die, but they don't disappear. Of course, this could be more to do with his desire for unchanging and perpetual youth than with his obsession with mortality, so you can still argue death = disappearing, even if you want to talk about the mummies.

You could also go in another (and perhaps darker) direction, and say the mummies aren't so much an uplifting example of preservation after death, but are more about lifeless shells – bodies without spirit, frozen physical forms, much like the fish (as Horwitz sees them) stuck in the frozen lake and absorbing nutrients through their pores. Maybe this is even how Holden sees himself.