In the early part of the 20th century, blood banks did not exist. Doctors transfused blood directly from the volunteer donor to recipient. Because the donor had to go to the precise site where the patient was being treated, this process became known as "blood on the hoof."
Some admirable and successful efforts were made to collect blood on the hoof. The most notable was set up by Percy Lane Oliver of the London Red Cross in 1921. Oliver established a city-wide panel of volunteers who were willing to respond at any hour, day or night. Each volunteer agreed to receive a physical exam, undergo tests for blood type and syphilis, and be entered into a phone log of people
to call if a donor was needed. At its height in the mid-1930s, Oliver's panel was answering more than 9,000 calls per year. Eventually such services were rendered obsolete by the development of the blood bank.
-- Douglas Starr
Photo: Percy Lane Oliver, from RED GOLD: THE EPIC STORY OF BLOOD, courtesy of the Oliver family.