The need for blood
Thanks to advances in blood transfusion practice and technology during the First World War, blood could be stored and shipped more safely during the Second World War - and therefore there was a greater need for blood donors.
Canadian Red Cross Society, Ontario Division, Mobile Blood Donor Service, appointment card to Luke Jeffery, Appin, Ontario, 24 May 1944
War, Memory and Popular Culture Archives - The University of Western Ontario - London, Ontario
postcard, 8.7cm x 13.9cm