allowed to go on sufficiently long, some will show polychro- 

 masia. 



b. The nucleus of the parasite is colored dark red and 

 sometimes the structure of the nucleus is discernible too. 

 The protoplasm is dark blue; brown pigment is present in 

 tertian, darker, sometimes nearly black, pigment in subter- 

 tian and quartan parasites. Tertian parasites show coarse 

 red Schuff tier's dots, except in the case of the youngest 

 forms. Subtertian parasites show Maurefs dots. The vacuole 

 shows no color just as the achromatic zone round the 

 nucleus. 



c. The thrombocytes are colored purple-red. 



d. The lymphocytes show a little too much color, al- 

 though their structure is still clearly discernible. 



e. The structure of the neutrophil cells comes out well 

 and the eosinophils are especially characteristic. The leuco- 

 cytes are a little too strongly colored. 



The results obtained from staining depend on the fol- 

 lowing: 



a. The nature of the stain. If the stain gives the erythro- 

 cytes a bluish tint and does not bring out Schiiffnefs dots or 

 only indistinctly in tertian parasites, matters may be im- 

 proved by adding a little eosin to the buffer fluid (1 to 

 30.000). 



b. The temperature. 



c. The concentration of the stain. 



d. Time allowed for staining. 



e. Time allowed for fixation. The longer the time al- 

 lowed for fixation the longer the period needed for staining. 

 If too little time is given to fixation haemolysis of the blood 

 cells may occur. 



/. The age of the film. The older the film, the longer the 

 time needed for staining. Insufficiently stained films are 

 immersed in Giemsa solution once more for re-staining. 



