98 Mosquitoes 



Its fever recurs every three days. It is relatively 

 much more common in temperate latitudes than in 

 the tropics. The entire intracorpuscular cycle is 

 completed in the peripheral blood, and here itssporu- 

 lating form is also more often seen than is the cor- 

 responding phase of the other malaria parasites. 

 There are more parasites, and therefore it is more 

 liable to recur, than the others. 



The pigmented parasite of quotidian malignant in- 

 fection gives rise to a fever of irregular duration. 

 Its gamete is a crescent. The unpigmented parasite 

 of quotidian malignant infection resembles it very 

 closely. Both these have a cycle of approximately 

 twenty-four hours; both exhibit very active ame- 

 boid movements when growing, and tend to assume 

 the ring form. They are much smaller than either of 

 the benign parasites, occupying from one-fifth to one- 

 third of the corpuscle only. They both form little 

 heaps of from six to eight very minute spores. In the 

 unpigmented parasite, pigment is never present ex- 

 cept in the crescent phase, when it is never absent. 

 The fevers to which both give rise usually run an 

 irregular course with dynamic tendencies, great 

 proneness to relapses, rapid destruction of blood 

 corpuscles, and the production of cachexia. 



The sub-tertian is the usual parasite of malignant 

 infection, resembling in many respects the tertian of 

 benign infection, but is much smaller, occupying 

 when mature only from one-half to two-thirds of the 

 corpuscle, which it alters in colour, sometimes caus- 

 ing it to shrink, shrivel, or double up. Its spores ( 

 usually ten or twelve in number, are arranged, along 



