ON HISTOGENESIS OF BONE MARROW IN RAT - INNERVATION STROMA AND THEIR RELATIONS TO HEMOPOIESIS

1. The early stages of development of the stroma of the bone marrow during the onset of the blood cell formation were studied in rats by combined histological and cytological methods. Special attention was dedicated to the study of the innervation of the fetal marrow in relation to the beginning of hemopoiesis. 2. During the 21st day of fetal life, the first nerve fibres can be demonstrated while the blood cell precursors as members of the erythropoietic or myelopoietic families can be recognized only one day after birth. 3. The early development of an innervated stroma that preceeds the differentiation of blood forming cells in the bone marrow, emphasizes the importance of the role of the stroma in this organ, and provides the marrow with a specific microenvironment that is adequate for the proliferation, differentiation and release of the blood elements. © 1969 Springer-Verlag Berlin Heidelberg.