YELLOW FEVER AND THE LEPTOSPIRA 875 



by the agency of mosquitoes was Carlos Finlay. Finlay, 2 as early 

 as 188.1, advanced the theory that mosquitoes were responsible for 

 the transmission of this disease and, furthermore, recognized "Ste- 

 gomyia fasciata" or "Stegomyia calopus" as the guilty species. 

 Finlay 's opinion, although later proved to be correct, was at first 

 based only upon such circumstantial evidence as the correspondence 

 of the yellow-fever zones with the distribution of this species of 

 mosquito and the great prevalence of mosquitoes at times during 

 which epidemics occurred. His theory was, therefore, received with 

 much skepticism and was neglected by scientists until its revival in 

 1900, when the problem was extensively investigated by a com- 

 mission of American army surgeons. 



Reed, Carroll, Agramonte, and Lazear were the members of this 

 commission. The courage, self-sacrifice, and scientific accuracy 

 which characterized the work of these men have made the chapter 

 of yellow fever one of the most brilliant in the annals of American 

 scientific achievement. 



Their work was much facilitated by the experience of Gorgas 3 

 and others, who had demonstrated the absolute failure of ordinary 

 sanitary regulations to limit the spread of yellow fever. 



They began their researches by investigating carefully the 

 validity of Sanarelli's claims as to the etiological significance of 

 his "Bacillus icteroides. " The results of this work yielded ab- 

 solutely no basis for confirmation. 



They then proceeded to investigate the possibility of an inter- 

 mediate host. 



In August, 1900, the commission began its work on this subject 

 by allowing mosquitoes, 4 chiefly those of the stegomyia species, to 

 suck blood from patients, later causing the same insects to feed 

 upon normal susceptible individuals. The first nine experiments 

 were negative. The tenth, of w r hich Carroll was the subject, was 

 successful. Four days after being bitten by the infected insect 

 Carroll became severely ill with an attack of yellow fever, by which 



2 Finlay, Ann. Roy. Acad. d. Havana, 1881. 



'Gorgas, Jour, of Trop. Med., 1903. 



*Eeed, Carroll, Agramonte, and Lazear, Phila. Med. Jour., Oct., 1900; also 

 Am. Pub. Health Assn. Rep., 1903; Agramonte, N. Y. Med. News, 1900; Reed, 

 Jour, of Hyg., 1902; Reed, Carroll, and Auramontc, Am. Medicine, July, 1901. 

 Boston Med. and Surg. Jour., 14, 1901; Carroll, Jour. Am. Med. Assn., 40, 1903; 

 Carrol, ' ' Yellow Fever ' ' in Mense, ' ' Handbuch der Tropen-Krankheiten, ' ' ii. 



