Just like McTeague, Trina reacts based entirely on instinct rather than thinking the situation through. Her responses are just as immediate and “natural” as the sickness that rises within her. While McTeague assumes Trina is sick from the ether, Norris is suggesting that the thought of marrying McTeague literally sickens her. This perhaps reflects the unnatural and potentially harmful effects of invented social norms, like marriage, which go against natural human impulses.