The physiological function of the pi (translated in English as spleen) in traditional Chinese medicine is generally known as the promotion of digestion. But the concept of pi has changed with the times. According to the Su Wen and the Ling Shy, the pi does not directly take part in digestion. These writings often describe the pi as the "pi merdian", considered to contribute to the function of the circulatory system. Comparing the descriptions of the pi in Su Wen and Ling Shu with those of the spleen in Dutch medical books published in the Edo period, we found the following similarities between these two different kinds of medical concepts. Both the pi in the former and the spleen in the latter are considered to be important in transportation of lymph. Furthermore, the pi meridian and jinye (body fluid) in the former correspond to the lymphatic vessel and lymph in the latter, respectively. ...