104 PLASMODIUM MALARIA 



blood corpuscle. These bodies increase in size, and 

 in them appear granules of black or reddish-black 

 pigment melanin derived from the haemoglobin 

 of the infected cell. These pigment granules, origi- 

 nally scattered and peripherally arranged, gradually 

 collect into groups or radiating lines, and finally con- 

 centrate into a more or less centrally arranged mass. 

 Around this the protoplasm of the parasite divides 

 into regularly arranged segments, which become cir- 

 cular and appear as well-defined spherules possessing 

 a vesicular nucleus and a nucleolus. These are the 

 spores (Fig. 108), and on their maturation the 

 red corpuscle breaks down, and the spores are set 

 free ; the melanin, which is not included in the 

 spores, also escapes. A proportion of these free 

 spores attach themselves to and finally enter other 

 red cells, and the cycle begins anew. The early 

 amoeboid movements become less as the parasite 

 matures, and cease before sporulation. After the 

 spore enters the blood cell, as may be seen in 

 stained specimens, the badly-staining nucleus in- 

 creases in bulk together with the protoplasm, and 

 the nucleolus comes to lie eccentrically. This eccen- 

 tricity of the nucleolus, and the relative size and 

 staining properties of the nucleus and protoplasm, 

 give the parasite a " signet ring " (Manson) appear- 



