A new technic of culture suspension of heparinized bone marrow is suggested. It consists in the use of a simple apparatus that permits a regular supply of oxygen and nutritive material to the cultured marrow. Tyrode's solution is homologous fresh plasma and extraction of chicken embryo circulated through a system in which waste products are removed. Cultures of normal and abnormal human bone marrow have been carried out with this technic.
When normal bone marrow is so cultured, it may be observed that in the first eight to fifteen days both specific marrow cells and fibroblasts are present in the tissue and will survive and show signs of moderate proliferation. In the second period, indefinite in time, only the fibroblastic elements survive and start a copious proliferation, as they are by then completely adjusted to the new medium. The proliferative and maturative changes of the specific elements are particularly evident