92 MANUAL OF HUMAN PROTOZOA 



dimensions. They are uninucleate and contain haemozoin 

 granules. The two kinds of gametocytes can be distin- 

 guished from each other as follows: 



Macrogametocytes Microgametocytes 



(Fig. 23, 11) (Fig. 23, i^) 



Cytoplasm Derser, stains more Stains less deep blue 



deeply 

 Nucleus Small, compact; more Large, elongate; less 



deeply stained deeply stained 



Haemozoin Coarser Finer; abundant 

 granules 



3. Plasmodium falciparum (Welch 1897) 



Synonyms: Laverania malariae Grassi and Feletti 1890 

 Plasmodium temie Stephens 1914 



This is the causative organism of the most malignant 

 malaria, known as subtertian, malignant tertian or aestivo- 

 autumnal fever. It is widely distributed in the tropics. In 

 the subtropical region, it is more prevalent in late summer 

 or early autumn. It is, however, relatively rare in the tem- 

 perate zone. The chill and fever appear every 36 to 48 

 hours, the schizogonic cycle being somewhat irregularly 

 periodic. 



Schizoiits 



1. Ring forms. Young ring forms are much smaller than 

 those of the other species (Fig. 24, l). They measure about 

 1.5n in diameter. Quite often marginal forms are en- 

 countered, and also multiple (2-6) infection (Fig. 24, 1) 

 often occurs in this species. The nucleus of the ring form 

 appears as a short rod or is divided into two granules 

 (Fig. 24, 1). In deeply stained smears, the infected host 

 cells may show red-stained granules (Fig. 24, 2-^), the 



