25 



The following forms of parasites may be 

 seen : — 



(i_) Small forms looking more or less like rings, 

 or stained streaks lying across or apparently stuck 

 to the side of the red cell. 



N.B. — Parasites free in the plasma are practically never 

 seen. 



(ii) Larger stained bodies of various shapes 

 and sizes more or less filling the cell. 



(iii) Crescents or large round or oval bodies 

 with a cluster of coarse pigment placed more or 

 less centrally. 



I. Ring Forms (Fig. 3). — 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 (chromatin), 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 unstained vacuolic area. 

 These rings stand out so sharply that they appear to 

 project from the corpuscles. The red dot gener- 

 ally 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 rod-shaped 

 or angular. The rings may shew a very faint 

 blue outline or a thicker portion on the side 

 opposite to the nucleus. 



Though generally called ' rings,' these para- 

 sites are really discs, or saucer-shaped bodies, 

 adhering to the sides of the red cells. 



Besides these young rings, we have irregular 

 forms of considerable variety, e.g., a mere faint 



