You might like to think of the way that words function as symbols in this excellent dystopian classic. Note the way in which Jimmy calls himself "Snowman" and savours the sound of words that are now obsolete in this brave new world. The reason why his head is full of all of these words is that he knows that when he forgets them they will be lost forever. This could be seen as a symbol for humanity in this novel. After the disease that Crake has unleashed, humanity is an endangered species, with Jimmy perhaps the one sole survivor, and, just as the words he uses will pass into obscurity, it looks very much as if humanity is heading that way too. Note the way in which there is a certain biting irony in Jimmy's name for himself. Naming himself after the "Abomninable Snowman," is, for Jimmy, a symbol of man's ephemeral nature, because it is "a white illusion of man... existing and not existing." Names therefore point towards the seismic change that has occurred and the passing of humanity.