260 SANITARY ENTOMOLOGY 



rily in the mosquito. There is indication of a granular stage of develop- 

 ment. The optimum temperature for development is 26° C. 



The earliest suggestions • of the possibility of mosquito carriage of 

 yellow fever were made by Josiah C. Nott in 184<8, and Dowler in 1855. 

 In 1881 Dr. Carlos J. Finlay made definite claims that the fever is car- 

 ried by the bite of a mosquito. In 1900 during the American occupation 

 of Cuba a commission composed of Doctors Walter Reed, James Car- 

 roll, Aristides Agramonte, and Jesse W. Lazear began the investigation 

 of the causation of yellow fever by first definitely discrediting the theory 

 of the Italian bacteriologist. Dr. Giuseppe Sanarelli, that his Bacillus 

 icteroides was the cause. This they proved to be identical with Bacillus 

 sui-pestifer. They then conferred with Dr. Finlay and began a thorough 

 investigation of the mosquito transmission theory. Dr. Finlay suggested 

 the common house mosquito, Aedes argenteus {Stegomyia fasciata) as 

 the cause. The members of the commission submitted themselves to the 

 making of the tests. Dr. Carroll was the first to take the fever, being 

 bitten twelve days after a mosquito had bitten a yellow fever patient. 

 In four days he took the fever. A week later Dr. Lazear, while conduct- 

 ing experiments, was bitten by a mosquito, which he allowed to engorge, 

 but to which he paid little attention. In five days he took the fever and 

 died in a Week. In the course of experiments ten cases of fever were pro- 

 duced at will by the application of infected mosquitoes, and all other 

 possible means of infection proved useless (see Reed, etc.). 



Dr. Guiteras (1901) confirmed the transmission of yellow fever by 

 Aedes argenteus {Stegomyia fasciata) in seven cases, three of which 

 proved fatal. Later a French commission, Marchoux, Salimbeni and 

 Simond (1903) in Brazil, and American commissions composed of Parker, 

 Beyer, and Pothier in Mexico (1903), and Rosenau, Parker, Francis, 

 and Beyer (1905), corroborated the transmission of the disease by this 

 mosquito. The last named authors tabulate the whole series of trans- 

 mission experiments showing that in 40 cases of transmission by mos- 

 quito bite, the incubation period after the bite exceeded three days and a 

 fraction in only ten cases, and was possibly less than three whole days 

 in only two cases. The maximum authentic record of the incubation 

 period is six days and two hours. 



Metazoa 



Platyhelmia : Fasciolidae 



A Clinostomum is rscorded by Soparker (1918) which passes its 

 first stage in a snail, Planorbis exustus, and is found as a cercaria in the 

 larvae and adults of Cvlex quvnquefasciatus (fatigans) and Anopheles 



