At the beginning of Chap. 13, Mr. Bennet tells his family about the impending visit of Mr. Collins. Mrs. Bennet (when she still thinks it is Mr. Bingley who is visiting) says, "But -- good lord! how unlucky! there is not a bit of fish to be got to-day. Lydia, my love, ring the bell. I must speak to Hill this moment". Why is that...is fish considered to be a desirable dinner choice for a special guest (as opposed to meat or fowl). Sorry if I missed this discussion elsewhere...