In higher vertebrates such as mammals, formation of white blood cells is restricted to bone marrow, the spleen and the lymph nodes. In fishes, organs such as the kidney, spleen and thymus take part in haematopoeisis.
In higher vertebrates such as mammals, formation of white blood cells is restricted to bone marrow, the spleen and the lymph nodes. In fishes, organs such as the kidney, spleen and thymus take part in haematopoeisis.