For Harry, death has been easy compared to the soldier who was impaled on the wire fence; in fact, death has become boring for Harry — he's as bored with it as he is with everything else.
Also, he tells his wife that "I've been writing." At this point in the story, Harry's intention is as good as his deed. In his current situation, Harry feels that he has done everything he can (in intention) to redeem himself and be worthy of Heaven before he dies. This is the final of the three deeds that facilitates Harry's eventual flight over Kilimanjaro.
At that moment, he feels "death come by again" — a hyena — resting its head on the foot of his cot.
Harry tells his wife, Helen: "Never believe any of that about a scythe and a skull." These traditional Western-world medieval symbols of death are not valid in Africa. Here, the vulture and the hyena dominate Harry's sure knowledge of his inevitable death. Indeed, the hyena becomes the more dominant symbol when it sits, "pressing," on Harry's chest.
