Abstract
Experimental studies of the regenerative activities of the bone marrow after traumatic exmedullation have been reported by many authors, e. g. by Bidder (1876), Maas (1877, 1878), Kumatori (1924), Muraoka (1929), and Horiuchi and
Ito (1929) among others. Hashimoto (1937, 1940, 1954) and Steinberg (1947) published their studies recently. Observations on the similar process after chemical injuries to the bone marrow have also been accumulated (Steinberg 1949). The majority of such studies are mainly concerned with the capacity of hematopoietic tissues to regenerate. This is particularly true because the primary injuries to the bone marrow are quite restricted or incomplete in these studies that their materials are not suitable in pursuing the dynamics of regenerative processes and interrelationship between the two different com ponents of the bone marrow tissues, i.e. the myelogenic hematopoietic tissues and non-hematopoietic mesenchymal elements.
Previous reports unanimously describe the regeneration of the hemato poietic bone marrow from the faily abundant ramains of such tissues in the uninjured portions. Thus, the process of regeneration occurs invariably rapid and the roles of the non-hematopoietic mesenchyme are apt to be obscured.
The author has been conducting a series of studies in this concern and, with a simple device to extract the bone marrow nearly completely, succeeded to observe the different behavior and interrelationship of the hematogenic and non-hematogenic mesenchyme in the reparative processes.
