This chapter introduces London's second, or parallel, theme of the novel. As a matter of historical and scientific information, the late nineteenth century had seen the emergence of Charles Darwin's theory of evolution, a theory which had become, by the time of London's novel, one of the most controversial scientific theories ever advocated. In a nutshell, the essence of Darwin's theory concerns the evolution of mankind — that is, was Man born as he is today? Or is he the end result of a series of evolutions from a more primitive species of life? In other words, in a more popular conception, is Man descended from apelike creatures? This theory, then, is further emphasized by London's use of the "survival of the fittest" (which also carries the opposite connotation of the elimination of the weakest). This chapter introduces Buck into the concepts of the survival of the fittest, and we will see how Buck is able to confront new and different situations, and how he is able to maintain his mastery of life — even in the most adverse conditions. In fact, at the very beginning of the chapter, London emphasizes this contrast: during Buck's first day, London tells us, "every hour was filled with shock and surprise. Buck had been suddenly jerked from the heart of civilization and flung into the heart of things primordial. No lazy, sun-kissed life was this, with nothing to do but loaf and be bored." In fact, Buck learned the law of the club rapidly in the previous chapter; now he will learn the "law of the fang." London is emphasizing that the respected laws of civilization have to be discarded if a man or a beast is to survive in this primitive situation. Buck learns immediately that he must be "constantly alert, for these dogs and men were not town dogs and men; they were savages." In this new society, Buck intuitively recognizes that only the strongest will survive. This is illustrated by the death of the good-natured dog called Curly, who, once he is wounded and down, is surrounded by thirty or forty other dogs, anxiously waiting to close in upon Curly, waiting for the primitive kill. What Buck witnesses is so unexpected and horrible that he is stunned by the entire episode, and, in fact, as he sees Curly's limp and lifeless body lying in the bloodied snow, he realizes that there is "no fair play" in this world, and that "once down, that was the end of you." In Buck's later life, he will often remember this gory, unjust scene; it will "trouble his sleep" many times. (We can thus anticipate that Buck's memory of this scene will cause him to hold his ground in later dog fights and to be savagely alert and bold.)
When Buck is harnessed to a sled by François, he is placed between Spitz, the lead dog, and Dave, "an experienced wheeler." (A "wheeler" is the dog nearest the sled.) At first, Buck resents being placed in a harness, as though he were merely some "draft animal" that he remembers from civilization, but Buck is too wise to rebel against this treatment, because he knows that François is "stern in demanding obedience, and Buck [knows] that he would not hesitate to use the whip." For the code of the Far North, the whip is tantamount to what the club was in Buck's first lesson concerning the "law of the club." Buck learns his duties very quickly, and one of the important laws of the primitive world is that one must learn quickly if one is to adapt to new situations and survive. For example, after his first day as a sled dog, Buck learns to "stop at 'ho,' and to go ahead at 'mush.'"
Buck's next learning experience involves the three new dogs that Perrault acquires. Two of these dogs, Billee and Joe, are huskies and brothers, but they are quite different in temperament. The third dog, however, Sol-leks (meaning "the angry one"), is blind in one eye, and he does not like to be approached on his blind side. Once, when Buck forgetfully approaches Sol-leks from the blind side, Sol-leks hurls himself upon Buck and slashes Buck's shoulder to the bone. Forever afterward, Buck avoids Sol-lek's blind side. Thus, continually, Buck learns an entirely new way of living and existing. Yet he and Sol-leks are not enemies because of the episode mentioned above, and until the death of Sol-leks, he and Buck are good friends.
Buck's next lesson in adapting to his new life involves finding a warm place to sleep. He sees lights one night in François and Perrault's tent, and because he has been used to sleeping by the Judge's fireplace, Buck enters their tent, only to be bombarded by curses and flying objects. Wandering around the camp site in the cold bitter wind, that is penetrating his wounded shoulder, Buck is surprised to find that all of the other dogs are, as it were, "teammates," and that they have buried themselves under the snow. Thus, Buck learns how the other dogs sleep and keep warm, so he selects a place for himself and is soon asleep; once again, he learns another lesson about how to survive in this new and hostile country.
Next morning, when Buck awakens, he feels the weight of the night's snow pressing down upon him, and "a great surge of fear swept through him — the fear of the wild thing for the trap." London, quite pointedly, goes on to say that this fear was "a token that [Buck] was harking back through his own life to the lives of his forebears." London writes, "the muscles of [Buck's] whole body contracted spasmodically and instinctively," and bursting out through the layer of snow, he sees the camp spread out before him. That day, Buck has another experience learning to be a sled dog, similar to the incident referred to earlier in these Notes. Buck is now placed between Dave and Sol-leks, who are both experienced dogs and who will teach Buck how to perform. When Buck makes a mistake, both dogs instantly "administer a sound trouncing to him." Buck learns very quickly, and at the end of that day, he is exhausted; after digging his hole in the snow, he falls quickly asleep.
For days, Buck is constantly "in the traces," and even though he is given a half pound of food a day more than the other dogs, he never seems to have enough, and he suffers from perpetual hunger pains. This is due partly to the fact that Buck is a civilized dog and a fastidious eater, and the other dogs wolf down their food, then come over and steal Buck's rations. Buck quickly learns, however, that in order to survive, he too must wolf down his food. In a civilized society, Buck would never have had to steal food, but now he realizes that in order to survive and thrive in this hostile northern environment, he will have to learn to steal in very secret and clever ways. According to London, Buck's thefts of food "marked the decay or going to pieces of his moral nature." But what Buck is learning is that in such a wilderness as this, his old sense of morality is a hindrance to survival.
Buck, however, reasons that in order to survive, he must adjust — in every way he can. It was one thing to respect private property in the Southland, where the law of love and fellowship reigned, but here in the Northland, "under the law of club and fang, it was foolhardy to observe any law that did not contribute to one's own personal survival." London writes that, although Buck did not exactly figure this out in "thoughts," the man in the red sweater had taught him about this very fundamental and primitive code. Buck's "decivilization was now almost complete because he did not steal out of joy," and "he did not rob openly, but, instead, he stole secretly and cunningly out of respect for club and fang."
Continuing with this concept of the survival of the fittest, Buck also soon learns that he can eat any type of food (even loathsome food) so long as doing so will help him survive. Furthermore, Buck's sight, his scent, and his hearing quickly develop a keenness which he never knew in civilized society. He is now even able to scent the wind, and he can tell what the weather will be like a night in advance. "And not only did he learn by experience, but instincts long dead had become alive again."
Carrying through with London's concept of naturalism (that maintains that there is a dimension of the primitive in all of us), Buck is beginning to remember back to ancient times before his own existence, to a time "when wild dogs ranged in packs through the primeval forest and killed their meat as they ran it down." Furthermore, on cold nights, Buck often points his nose toward the sky and howls like a wolf; "it was as though his ancestors . . . [were] pointing their noses at the stars and howling down the centuries and through him." This anticipates the final chapter of the novel when Buck will be seen roaming the forest with the wolf pack and will be seen answering the call of the wild by howling with the other wolves.