Leon Rasmussen, who penned the Bloodlines column for many years in Daily Racing Form, died today of cancer. He was 88.Rasmussen, who would have been 89 Aug. 26, is survived by his wife, Erna. No services are planned for Rasmussen. He was employed by Daily Racing Form for 50 years, contributing his featured "Bloodlines" column for 37 of those years. It was Rasmussen who popularized the theory of dosage, particularly when it came to handicapping the Kentucky Derby.A pedigree expert, Rasmussen also believed strongly in the theory of superior inbreeding to female families. In 1999 with Rommy Faversham, he authored the book, "Inbreeding to Superior Females." He was the co-compiler of the book "The Treasures of the British Bloodstock Review" and was the author of the relevant chapter on "Hyperion" by Clive Graham, a reprinted work that examined that stallion's career and worldwide influence.Contributions may be made in his memory to the American Cancer Society or the Don MacBeth Memorial Jockey Fund.