This four issue Dark Horse comic book series proposes what would happen to Tarzan if Jane died. It's sort of the last straw-and he realizes that the best place to be, for him, to regain the freedom he had as a youth, is to go to Pellucidar, the world that exists in our hollow earth. Once there, he witnesses a woman being attacked by Thipdars (pterodactyls) but chooses not to help her since it's "the law of the jungle" of the weak being food for the strong. Later, though, he has second thoughts about this decision. Then, he befriends a group of ape-men who understand his ape language. However, they are vegetarians-and when he doesn't want ago eat their melon there's a fight. He ends up fighting the king-and wins-but that's the last thing he wants, is the responsibility of being the leader of a tribe.
THE SAVAGE HEART is one of the better Tarzan comic tales. Highly recommended.