ENTOMOLOGY

DISEASES TRANSMITTED BY MOSQUITOE..s !59ciana, intermedium, mcdiopwnctatus, p8eudomaculipe8, punctiptmll/,ia, andquadrimactdatua, three of which species occur in the United States.AVIAN MALARIA.-Several forms of avian malaria are known.Pla8modium danilewsky Grassi and Feletti (1890), a malaria of sparrows,partridges, finches, and crows is carried by Culex quinquefaaciatua(faUgana) , C. pipUma, Aedes 'IUfflWro8'IJ..s Meigen, and A. argewtCIAB( calopus) according to various textbooks.Plasmodium relictum, a malaria of the canary, was proven by Sergentand Sergent (1918) to be carried by Culex pipiena.Mastigophora: Spirochaetacea: SpirocTtaetidaeSpiroachaudinnia culicia Jaffe (1907) was found by Jaffe in thegut ,and malpighian tubules of Culex pipiens and Anopheles mactdiptffl/11,ia.Leptospira icteroidea Noguchi (1919) has been proven to be thecausative organism of YELLOW FEVER in investigations made inEcuador. Noguchi obtained pure cultures by inoculation of guinea pigswith blood of yellow fever patients. He isolated the organisms fromthree patients and also from mosquitoes and inoculated them into guineapigs, dogs, and marmosets (Midaa oedipua and M. geoffroyi). Theorganism is filterable.This dread disease of the tropics has been studied for years andmany other investigators have sought the organism without success. Seidelin,in 1909, described a parasite belonging to the Babesiidae in theblood and organs of yellow fever patients, as Paraplasma flavigmum,which he considered to be the cause of yellow fever, but this organismwas not generally accepted as the causative organism. The incubationperiod in man is three days and the mosquito to become infected must bitea patient during the first three days of his illness, and then twelve daysmust elapse before the infected mosquito can transmit the disease to man.The organism of yellow fever may pass through the pores of a PasteurChamberlain B. filter. The disease can be conveyed by subcutaneous injectionof the blood taken from the general circulation of a person sickwith the disease during the first three days of the disease, but can becarried nnturally only by the bite of a mosquito (Aedea argentCUB, usuallycalled Stegomyia fa8ciata), tha.t at least I! days before has fed on ·theblood of a person sick with this disease, during the first three days of hisillness. But Noguchi transmitted it by the bite of a mosquito from adiseased to a. healthy guinea pig in 8 days and 8-1!il days, and from manto guinea pig, ll3 days after biting"man. Prophylaxis therefore consistsin prevention of biting by mosquitoes, and mosquito extermination.There is no definite proof that the virus can be transmitted heredita-