MORPHOLOGY OF BLAST CELL NUCLEI IN VIVO AND IN VITRO

This paper describes and illustrates the behavior of blast cell nuclei recorded by a motion picture camera through a phase contrast microscope. This behavior includes extension and contraction of the nuclei to present the classically accepted patterns of a rounded nucleus at one moment and an elongated often twisted shape a few seconds later. The motion involved is not amoeboid action. The elongated nucleus is not accepted in the literature as a normal pattern of a blast cell nucleus but it obviously should be. After an extension the nucleus contracts again presenting the classical rounded form commonly associated with blast cells.The authors believe that this nuclear behavior is a natural function of the blast cell and that it occurs many times during the life history of this cell. It is especially characteristic of the time when the blast cell is releasing most of its nuclear contents to form free basic nuclear units and other components of the blood. A comparison is made with similar blast cells and their nuclear variations in a Feulgen "gentle squash" preparation which is lightly counterstained with fast green F.C.F.