Manual of pathology : including bacteriology, the technic of postmortems, and methods of pathologic research . nce closely resembling poikiloc3tosis, butdevelops after the blood has been drawn. Crenated cells are irregular,and show knobbed projections from their surfaces associated with moreor less shrinking of the protoplasm; by some it is believed that crena-tion is the extravascular analogue of intravascular poikilocytosis. Early in fetal life the nucleated red blood-cells normally present atthat period begin to disappear, and at birth, or shortly after, are nolonger present in the normal b
Manual of pathology : including bacteriology, the technic of postmortems, and methods of pathologic research . nce closely resembling poikiloc3tosis, butdevelops after the blood has been drawn. Crenated cells are irregular,and show knobbed projections from their surfaces associated with moreor less shrinking of the protoplasm; by some it is believed that crena-tion is the extravascular analogue of intravascular poikilocytosis. Early in fetal life the nucleated red blood-cells normally present atthat period begin to disappear, and at birth, or shortly after, are nolonger present in the normal blood. In certain morbid conditions,however, they form conspicuous hemal elements. It is usually heldthat at some stage in its evolution the red blood-corpuscle possessesa nucleus, which disappears before the cell assumes the function ofa hemal cell. Exactly how this disappearance of the nucleus is accom-plished has not been accurately determined. According to some ob-servers, the nucleus disappears by extrusion, while others think it isremoved by a process of absorption or of disintegration. The nucleated. TlIK ). 40(> cells soon in the blotx,! are of dilTerent sizes, justil\in}^ U) a certain ex-tent the division into three kinds. Normoblasts are nucleated retl cells the ilianicter of which is ap-proximately that of the normal erythrocyte. The size of the nucleusvaries, ami it is usually eccentric in location. It is rich in chromatin,stains with intensity li\ tlio usual nuclear stains, and not uncommonlycontains a fine, intranuclear net. Occasionally, the nucleus will lie foundpartly outside of the ])rotoplasm—a condition that suj^j^^csts its extru-sion. Sometimes, in properly fixed pre])arations evi(lences of mito-sis may be present, or the cell may contain two or even three nuclei;these may appear distinct and separate, while in other cells connectingbands of chromatin may be recognized. The perinuclear protoplasmcontains more or less hemoglobin, and hence stains wi
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