nF.viRw — TKorrcAty sfedtcink, etc. 237 



either by day or by night, from the first clay of its adult life. After a few days, however Yellow 

 — particularly after laying her first batch of eggs — the female only bites during the night, Fever— 

 and it therefore follows that man becomes infected almost invariably during the hours of contimml 

 darkness. Their experiments on the conveyance of yellow fever by mosquitoes other than 

 S. fasciafa, proved negative. In most other species of mosquito the female invariably dies 

 immediately after laying her first and only batch of eggs, and this circumstance hardly 

 admits of sufficient time for the virus to develop within her. Marchoux and Simond 

 observed that the female S. fasciata was capable, after having bitten yellow fever 

 patients, of transmitting to its offspring the power of infecting other human subjects with 

 the disease ; but Eosenau and Goldberger^* failed to corroborate this. The French 

 Commission-'* further notes that the S. fasciata requires human blood for the development 

 of her eggs, and that when the blood in dead, infected StegomyicV is ingested by non-infected 

 mosquitoes, infection of the latter results. 



Among the special characters of the S. fasciata which affects its role as a carrier of 

 yellow fever. Carter^* notes the fact that it can be conveyed by vessels indefinite 

 distances, and in greater numbers in sailing vessels than in steam-ships. It appears to 

 have a long life-history, 15i days being recorded as the duration of life of an infected 

 insect ; further, it is a domestic mosquito, breeding in cisterns, yards and puddles. 



With reference to the longevity of the S. fasciata on sailing vessels, a serious question 

 arises in connection with the spread of yellow fever into Asia via the Panama Canal. 

 Manson'** was the first to direct the public attention to this all-important point, and 

 recommended systematic examination and thorough prophylactic measures adapted towards 

 the destruction of the Stegomijia on all vessels passing through the Canal. Although the 

 excellent work of Eeed and other observers has most conclusively shown that the 

 Stegomijia fasciata is the transmitting agent of the yellow fever virus, it is of interest to 

 note that quite recently Ybarra,'* in an epidemic which occurred in Cuba, quotes nine 

 cases in which the disease developed after six days' hypothetical exposure to the supposed 

 mosquito infection, but in reality this mosquito infection, he says, could not possibly have 

 existed, and he therefore disputes the theory that the mosquito is the exclusive carrier of 

 the disease. 



Various experiments, too numerous to be mentioned here, have been carried out in 

 connection with the virus of yellow fever. Marchoux and Simond found that the virulent 

 serum lost its efScacy at a temperature of 55° C, a point which was previously observed 

 by Eeed and others, and that the serum loses its power of infection after exposure for 

 48 hours to the air ; further, if kept at a temperature of 24°-30° C, it is powerless at the 

 end of 48 hours. 



Attempts by Marchoux and Simond to infect animals with yellow fever by 

 submitting them to the bites of infected iS. fasciata failed. Wolferstan Thomas," however, 

 succeeded in infecting a chimpanzee with a benign attack of yellow fever, when infected 

 Stegomyise were allowed to feed on it. 



The incubation period of yellow fever is usually three days, sometimes five, and in one 

 authenticated case six days, but the French observers, Marchoux and Simond, extend it 

 to thirteen. It is beyond the scope of this Eeview to discuss the symptoms and treatment, 

 but mention may be made of the success obtained by Sternberg's method of treating his 

 cases with alkalies, and, judging from statistics, this method augurs well. The question of 

 prophylaxis is an important one, and one which should be carried out vigorously from the 

 outset. Non-infected Stegomyiie should be prevented from biting the sick, and infected ones 

 from biting the healthy. To this end all collections of water should be abolished or covered 

 with oil, and all cisterns covered with copper-wire gauze. Early notification is essential. 



The patient should be segregated during the infective period and infected mosquitoes 

 prevented from escaping from the room. All doors, windows and apertures should be 

 securely screened with gauze, and so also the patient's bed. While the breeding-places are 



' Rosenau, — and Goldberger, — (1906), Yellow Fever Institute, Bulletin No. 15. 



^ (June loth, 1906), "French Commission to Rio." Journal of Tropical Medicine. 



' Carter, — (May 14th, 1904), "Some Characteristics of Stegomyia Fasciata, which affect its conveyance 

 of Yellow Fever." Medical Record. 



* Manson, P. (March 7th, 1903), " Introduction of Yellow Fever into Asia." Lancet. 

 ^ Ybarra, A. M. P. (October, 1907), " Recurrence of Yellow Fever in Cuba." Texas Medical Joicrnal. 

 « Thomas, W. (January 19th, 1907), " Yellow Fever in the Chimpanzee." British Medical Journal. 



' Article not consulted in the original. 



