i8 



NEW YORK STATE MUSEUM 



this disease. These germs may be carried by man in a latent con- 

 dition for years. This is especially true of Italians. The sequence 

 of events may be briefly summarized as follows : A female mosquito 



bites a person having malarial 

 germs in his blood. The malarial 

 parasites enter the walls of the 

 mosquito's stomach, undergo cer- 

 tain changes therein, and in from 

 7 to 14 days make their way to 

 the salivary glands and are then 

 ready to enter the system of the 

 next person bitten. These germs 

 then undergo a series of changes, 

 and if the person is not immune a 

 more or less severe case of malaria 

 develops. So far as known, the 

 malarial mosquito, and that only, 

 r , can carry this infection. The 



mosquito, lemale, -^ 



with male antenna at right and wing tip counectiou bctwcen malaria and 



showing venation at lett. ( Keduced from 



Howard, U. S. Dep't Agric. Div. Ent. exteusivc 



iiul. 25. n. s. 1900) 



excavations has long 

 been recognized, though it is only 

 recently that a satisfactory explanation of this condition has been 

 advanced. Malarial mosquitos breed in large numbers in pools in 

 and about excavations. Italians are our principal excavators. 

 Most of them have suffered from malaria and have the disease germs 



Fig. 4 Common and malarial mosquitos at rest, the latter to the right. (Reduced 

 from Howard, U. S. Dep't Agric. Div. Ent. Bui. 25. n. s. 1900) 



in their systems. The malarial mosquito, breeding m large numbers 

 about recent excavations, derives its infection from the Italians 

 and then, if opportunity allows, inoculates Americans. We 



