DEVELOPMENT OF THE BLOOD-FORMING TISSUES OF THE TAMMAR WALLABY MACROPUS-EUGENII

The development of the haematopoietic tissues of the tammar wallaby Ma cropus 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 an d stem cells present in the circulation. By Day 3, the spleen shows li mited haematopoietic activity and by Day 12 contains areas of erythroi d and myeloid cells, At two weeks after birth, the haematopoetic activ ity in the liver declines and small areas of haematopoiesis are appare nt in the bone marrow, By the end of the first month, the bone marrow appears to be the major site of haematopoiesis.