Development of the blood-forming tissues of the tammar wallaby Macropus eugenii.

The development of the haematopoietic tissues of the tammar wallaby Macropus eugenii follows a similar pattern to that observed in eutherian and other metatherian mammals. At birth, the liver appears to be the only site of haematopoiesis with significant numbers of neutrophils and stem cells present in the circulation. By Day 3, the spleen shows limited haematopoietic activity and by Day 12 contains areas of erythroid and myeloid cells. At two weeks after birth, the haematopoetic activity in the liver declines and small areas of haematopoiesis are apparent in the bone marrow. By the end of the first month, the bone marrow appears to be the major site of haematopoiesis.