perature, the concentration of the stain, the age of the film, 

 and the effectiveness of the stain used. A slide that is a day 

 or two old does not stain as well as a freshly made one. 



A thick drop is well stained if above a white ground it 

 shows a purple color after flushing. Films are always bluer 

 in tint after drying than before. 



A film that has been stained for too short a period or too 

 lightly is tinted pale to dark blue. This means that the red 

 component has not had time enough to act and one notes 

 among other things the absence of Schiiffner's dots. 



Flushing should be done by pouring water carefully over 

 the slide beginning at one end, care being taken not to allow 

 the metallic looking film, floating on the stain, to come in 

 contact with the bloodfilm as this would produce a trouble- 

 some precipitation. Never dry the slide by artificial heat or 

 by putting it in the sun. 



If a thick drop is properly stained, the microscope reveals 

 a colorless or slightly yellowish background, not blue. The 

 thrombocytes will be red-violet. The structure of the leuco- 

 cytes should stand out clearly, even if they are rather 

 strongly colored. 



The stroma of the polychromatic erythrocytes, as well as 

 basophile stippling, should be visible in the form of a blue 

 "network" and easily distinguishable as forming fine or 

 coarse nets. 



The parasites have a red nucleus. The protoplasm is dark 

 blue; the larger parasites show dark brown to black pieces 

 of pigment. The erythrocytes with tertian parasites are 

 stippled with orange red or purple red Schiiffner's dots; 

 those with subtertian parasites show red spots (Maurer's 

 dots). 



When the film is too lightly stained the Schiiffner's dots 

 or Maurer's dots do not show and the protoplasm of the 

 parasite is tinted a too pale blue. 



When the staining is too strong the parasite is shrivelled 

 and unrecognizably covered by blue coloring matter and by 

 red streaks due to colored threads of fibrin. 



