Max Schultze published the first accurate and convincing description of platelets as part of a study devoted mainly to the white blood cells in 1865. He recognised them as a normal constituent of the blood and ‘enthusiastically recommended’ them as an object for further study by ‘those concerned with the in-depth study of the blood of humans’. In 1882, Bizzozero demonstrated the value of this recommendation in his much more comprehensive study. He observed them microscopically in the circulating blood of living animals and in the blood removed from the blood vessels. In well-planned experiments, he showed that they were the first component of the blood to adhere to damaged blood vessel walls in vivo and, in vitro, that they were the first components of the blood to adhere to threads that subsequently became covered with fibrin.