<prompt> In embryo, Hemopoiesis is first demonstrable inYolk sacLiverSpleenBone marrow  <response>: In the early embryo, hemopoiesis is demonstrable first in the yolk sac, followed by the liver and finally bone marrow.Reference: William;s Obstetrics; 24th edition; Chapter 7; Embryogenesis and Fetal Morphological Development 