The Practical Study of Malaria 



Chapter I{ 

 THE NORMAL CONSTITUENTS OF THE BLOOD 



NORMAL blood should be carefully studied in 

 fresh, and stained specimens. 



1. Red Cells (or normocytes). 6-9/4. In fresh 

 films they show a very faint central pale area. The 

 colour on staining with Romanowsky (p. 21) varies 

 with the amount of washing ; generally it is greenish 

 or bluish, or faint eosin ; with Leishman, Giemsa, 

 etc., a deeper eosin colour. 



2. Platelets. 2-4^. Vary much in size and 

 shape. They frequently occur in masses in wet films 

 and if examined an hour or so after formation these 

 masses exude colourless drops of secretion best seen in 

 4 vital staining ' specimens (Ross). They stain bright 

 crimson with Romanowsky and lie in clumps of from 

 six to fifty. They do not shew the red, white, and 

 blue of a well-stained parasite but stain diffusely 

 crimson or blotchy violet (Fig. 2). 



3. Blood dust (or Haemaconiae). Refractive 

 granules, smaller than micrococci, at most l/j, in 

 diameter. They shew active motion (Brownian) in 

 fresh films. They are probably granules escaped from 

 leucocytes. 



