Fannie Farmer,
Boston Cooking-School Cook Book
(1918)
“ If the outside skin comes off easily, mutton is sure to be good. Lamb chops may be easily distinguished from mutton chops by the red color of bone. As lamb grows older, blood recedes from bones; therefore in mutton the bone is white. In leg of lamb the bone at joint is serrated, while in leg of mutton the bone at joint is smooth and rounded. Good mutton contains a larger proportion of fat than good beef. Poor mutton is often told by the relatively small proportion of fat and lean as compared to bone. ”
