i8 ' - 



2. Leucocytes. — The following types should 

 be clearly made out in stained films : — 



The Polymorphonuclear Leucocytes (Fig. 2). — 

 These are very characteristic, and a reference to 

 the diagram will make their recognition easy. It 

 will be noted that they have a very irregular 

 nucleus and fine granulations (stained red by 

 Romanowsky). 



The Small Mononuclear Leucocytes (Fig 2). — 

 These, the lymphocytes, are readily seen and can 

 scarcely be mistaken for other forms. Their ap- 

 pearance varies somewhat with the thickness of 

 the film. The thinner the film the larger they 

 appear and the greater the area of protoplasm 

 surrounding the nucleus. In typical forms the 

 nucleus is dark staining and nearly spherical. 



In wet films, a proportion of these cells shew 

 a dark refractile spot (Manson's spot), which 

 might be mistaken for a pigment granule, but, as 

 we shall see later, they cannot possibly be confused 

 with a typical pigmented leucocyte. 



The large Mononuclear Leucocytes (Fig 2). — 

 It is well to get thoroughly familiar with the 

 appearance of this type of leucocyte, as the per- 

 centage of these is of great diagnostic importance 

 in malaria. 



Typical large mononuclear leucocytes are 

 readily and clearly distinguishable. They are the 

 leucocytes which may contain malarial pigment, 

 and the recognition of a pigmented leucocyte gives 

 a clear idea of their characters. 



(i) They are in thin films of considerable size, 

 half as much again to twice the size of the small. 



(ii) The nucleus is large, oval, eccentric^ not 

 nearly so dense as in the case of the small — as is 



