6 
nucleus is frequently eccentric and may be slightly 
indented, and does not stain so deeply as the young 
nucleus. The protoplasm is fairly wide and often 
shews some reddish granules with Romanowsky. These 
forms are not always easily distinguished from large 
mononuclears, the greater size of the latter and the 
character of the nucleus are the main distinctive 
features. These old forms constitute one of the cells 
known as makrophages. They sometimes contain 
malaria pigment (Fig. 2). 
Many of the lymphocytes in fresh films shew a 
spot at the edge of the cell (Manson’s spot). The spot 
looks dark in one focus, light in another, and should not 
be mistaken for a pigment granule. 
Fig. 3. Myelocytes. Left , Eosinophil; right , Neutrophil 
Large Mononuclear Leucocyte. —10-20/z, the largest 
leucocyte in the blood. It has a characteristic irregular 
much-mdented nucleus which stains feebly, quite 
distinct from that of the old lymphocyte. The proto¬ 
plasm is broad and may shew a few azure granules with 
Romanowsky. It also is a makrophage, and is the 
typical pigmented leucocyte of malarial blood (Fig.2). 
Transitional .—About the same size as large mono¬ 
nuclears, and the nucleus is of the same general nature ; 
but the lobed indented character is much further 
developed, being trident or S-shaped. They are not 
uncommon in malarial blood and are counted with the 
large mononuclears (Fig. 2). 
