haematoblast

he·ma·to·blast

(hē'mă-tō-blast)

A primordial, undifferentiated form of blood cell from which erythroblasts, lymphoblasts, myeloblasts, and other immature blood cells are derived; in normal bone marrow, present only in small numbers and difficult to identify in smears, because hematoblasts are fragile and easily disintegrated.
Synonym(s): hematocytoblast, haematoblast.

[hemato- + G. blastos, germ]

haematoblast

the parent cell of red blood corpuscles.