776 PATHOGENIC PROTOZOA 



1. Tertian malaria is distinguished by a chill and fever occurring 

 every other day, the patient feeling quite well on fever-free days. A 

 double tertian infection occurs not infrequently, giving a daily, or 

 quotidian, chill and fever with no free day. 



2. Quartan fever, which is relatively rare, gives a chill and fever 

 every third day, with two fever-free days. In this disease also there 

 may be double or even triple infections, giving a quotidian or irreg- 

 ular type of fever. 



3. ^Estivo-autumnal fever (subtertian, or malignant tertian) shows 

 an irregular temperature curve, the cycle varying from twenty-four 

 to forty-eight hours. By some authors the disease is divided into 

 two forms, quotidian and tertian ; and as multiple infections are com- 

 mon the resulting fever curve may be irregular or continuous and the 

 chill entirely absent. In contrast to the regular intermittency of ter- 

 tian and quartan this form is often remittent, the temperature curve 

 never dropping to normal. 



4. Mixed infections with any two of the above fevers are often 

 found in bad malarial regions in the tropics. 



5. Latent malaria is also not infrequent, in which the patient, hav- 

 ing no symptoms of the disease, consults a physician for some other 

 reason. 



6. The carrier state is found among natives or persons long resi- 

 dent in malarial regions, and, aside from the presence of a large spleen 

 and some secondary anemia, may present no symptoms. It is particu- 

 larly common among native children, tramps and vagabonds. It is not 

 uncommon to find fifty to one hundred per cent of the children in a 

 native village harboring the parasite. 



THE DEVELOPMENT OF THE HUMAN MALARIAL PARASITE 

 IN THE MOSQUITO 



(Sexual half of the life cycle, Sporogonie) 



For this stage to be successful the mosquito must bite a malarial 

 patient with gametes in his blood, for if the patient be one in the first 

 stage of the disease, with only schizonts in his blood, no infection of 

 the mosquito will take place, since the schizonts all perish in its 

 stomach. On the contrary, if the mosquito takes blood from a per- 

 son who has been ill with malaria for some time, or from an appar- 

 ently healthy carrier, the schizonts die as usual, but the gametes find 

 in the mosquito stomach for the first time conditions suitable for 

 their further development. 



