film can be put away and kept indefinitely. If not 

 needed the slide is placed on one side with others, 

 and eventually cleaned.* 



THE DETECTION OF THE MALARIA PARASITE 



We may first note that it is not necessary to 

 examine the blood at any particular time, but it is 

 very necessary that the patient should net have taken 

 quinine previously. Even five grains of quinine may 

 so diminish the number of parasites as to make detec- 

 tion a laborious task, and a negative result under these 

 conditions is not conclusive. 



The following forms of parasites may be seen : 

 N.B. Parasites free in' the plasma are practically never seen. 



I. Ring Forms (Fig. 6). These may be quite 

 small, one-sixth of a red cell in diameter, or much 

 larger, one-third in diameter. 



Rings are parasites of very distinct outline and 

 structure. The part of the parasite that will first be 

 noticed in a Romanowsky specimen will be the red 

 nucleus, a clearly stained bright red dot (or dots). 

 This is generally situated on the margin of the blue 

 ring, which is equally distinct in outline, though often 

 only a faint blue. The blue ring encloses an un- 

 stained ' vacuolic ' area. These rings stand out so 

 sharply that they appear to project from the corpuscles. 

 The red dot generally forms the signet of the ring 

 (signet forms), but also may occur in the centre of 

 the vacuole. The red nucleus or dot is often also 



* To CLEAN DIRTY SLIDES 



i. Rub with turpentine (benzine or xylol) to remove any adherent oil. 

 2. Wash with soap and'water. 3. Rinse in water. 4. Dry and rub well with a 

 clean cloth. 



