Concentration of Megaloblasts: An Aid in the Diagnosis of Pernicious Anaemia.

The buffy coat in a haematocrit tube consists of white cells, which, in spite of their larger size, fall with less velocity than the smaller red cells. This consideration suggested that the bigger, nucleated red cells might be found in increased numbers in or immediately beneath the white cell layer, and this has proved to be the case. Incidentally, both macrocytes and microcytes are found concentrated in this agea, thus exaggerating the typical pernicious anaemia picture. A further point of interest is the study of the white cells themselves, which in ordinary films are very scarce, owing to the generally occurring leucopenia. Cooke's Type I and II cells can thus be conveniently studied.