ABSTRACT
The hematuria of the domestic chicken has been monitored during its embryonic development. It was followed in one instance during the tenth to the eighteenth day of incubation and in another investigation from day 5 of incubation through hatching plus three days post-hatch. Both studies generated experimentally equivalent hematocrit-development curves. The neonatal erythrocytic picture of the white Plymouth Rock chick was reported by Dixon and Torbert. At hatching the erythrocyte count and hemoglobin concentration were high. At two days of age numerous immature rbc were seen to enter the peripheral circulation and the hemoglobin level and the number of erythrocytes began to decrease. The size of the erythrocyte quantitated by linear measurements revealed a rather sharp diminution in size during the first two weeks. Erythropoietin-supplementation of cultures of de-embryonated chick blastodiscs moderately enhances the synthesis of hemoglobin in this tissue.
