In Chapter 20 of The Sea-Wolf, Larsen makes light fun of Humphrey in front of Maud. What is his purpose for doing so?
Passages that might help:
Not that he is much to speak of now,” Wolf Larsen went on, “but he has improved wonderfully. You should have seen him when he came on board. A more scrawny, pitiful specimen of humanity one could hardly conceive. Isn’t that so, Kerfoot?”
Look at him now. True, he is not what you would term muscular, but still he has muscles, which is more than he had when he came aboard. Also, he has legs to stand on. You would not think so to look at him, but he was quite unable to stand alone at first.”
The hunters were snickering, but she looked at me with a sympathy in her eyes which more than compensated for Wolf Larsen’s nastiness. In truth, it had been so long since I had received sympathy that I was softened, and I became then, and gladly, her willing slave. But I was angry with Wolf Larsen. He was challenging my manhood with his slurs, challenging the very legs he claimed to be instrumental in getting for me.
"Mr. Van Weyden is sometimes - how shall I say? - er - quarrelsome, and harsh measures are necessary. He is quite reasonable and fair in his calm moments, and as he is calm now he will not deny that only yesterday he threatened my life.”
I was well-nigh choking, and my eyes were certainly fiery. He drew attention to me.
“Look at him now. He can scarcely control himself in your presence. He is not accustomed to the presence of ladies anyway. I shall have to arm myself before I dare go on deck with him.”
Wolf Larsen is a hateful and mean character. He is feared and despised by his crew and the people on board the "Ghost," but he is so strong and in charge that no one dare cross him. In this chapter he is having dinner for the first time at sea with a woman at the table. His testosterone is kicking in and he is trying to "impress" the lady. As with many men like Larsen, the only way he knows to build himself up is to tear others down. He verbally attacks Humphrey because he can, and as Humphrey himself thinks,
"He was challenging my manhood with his slurs, challenging the very legs he claimed to be instrumental in getting for me."
The only reason a man would do this in front of a woman is to make himself appear stronger and more appealing.