[The occurrence of phenoloxidase containing cells (= POZ) during the embryonary development of the hen (POZ-cells of the immunological system?) (author's transl)].

By means of the phenoloxidase reaction it would be shown that the POZ appear in haemopoetic cell islands of the yolk sac being hatched 6 days and being hatched 11 days, they appear in embryonary tissues. Favoured target organs are the spleen and the bone marrow, though also at the same time can be seen some cells in the connective tissue of the embryo. POZ can also be found in the bursa of FABRICIUS. The participation of the POZ in immunological reactions is supposed.