In the light of recent advances in human hematology employing the study of bone marrow, it seemed that similar technics might be employed in veterinary medicine. In human medicine bone marrow studies have been found to be valuable in the diagnosis of obscure conditions, particularly anemias, leukemias, myelomas and cancer, to confirm diagnoses, as an aid in the understanding of disease processes and in the bioassay of drugs. A search of the literature failed to reveal any available studies on the bone marrow of our domestic animals with the exception of the dog.