This volume serves as a supplement to the eponymous handbook article by Adele Hartmann from 1930. At that time, splenology was in a certain state of stagnation from a morphological standpoint. The microscopic study of the spleen had reached a preliminary conclusion with Weidenreich and Mollier, and since Sobotta's summary, there had been nothing significant added, aside from the works of Hueck and a few others. In contrast, experimental physiology had received a significant boost from Barcroft's investigations into the blood storage function of the spleen, which should indirectly also influence morphology: the question of the extent to which the results obtained from dogs and cats apply.