This volume is a collection of the presentations given at the sixth international research conference, Blood Cells as a Tissue, at The Lankenau Hospital, October 30 and 31, 1969. The conference was supported in part by the following pharmaceutical industries: Abbott Laboratories, North Chicago, Illinois; Baxter Laboratories, Inc., . Morton Grove, Illinois; Bristol Laboratories, Syracuse, New York; Burroughs Wellcome and Company, Tuckahoe, New York; Eli Lilly and Company, Indianapolis, Indiana; Geigy Pharmaceuticals, Ardsley, New York; Merck Sharp & Dohme Post Graduate Program, West Point,...