DISTANCE OF FLIGHT 343 



ship " Concho," Key West to Galveston, as follows : " Civil data Aug. 6, '09 ; 

 Ship's time 10 a. m. ; Latitude 38.40 ; Longitude (Greenwich) 92.30; Cloud of 

 mosquitoes large, lazy and hungry. Wind N, E. Moderate at the time. The 

 above mosquitoes were about 60 miles from the nearest land. I never before ex- 

 perienced mosquitoes over 5 miles from land, and only a few times even at that 

 distance." Xo specimens of the mosquitoes were received, but in view of Mr. 

 Mitchell's observations quoted above, there seems no reason to doubt the explicit 

 record of Captain Young to the Hydrographic Office of the United States gov- 

 ernment. 



Grubbs, in a paper previously quoted, in the course of his investigations of 

 vessels as carriers of mosquitoes, at the Gulf Quarantine Station, concludes from 

 evidence submitted that in seven cases of sailing vessels in the Gulf of Mexico 

 mosquitoes came aboard ; in two instances two miles from shore, in one instance 

 ten miles from shore, in three instances fifteen miles, and in one instance twenty 

 miles. Among these mosquitoes there were no malarial or yellow fever forms, 

 all belonging to species of Aedes. 



The following paragraphs are taken from a letter received in 1903 from 

 Surgeon A. C. H. Eussell, United States Navy, of the U. S. F. S. " Newark," 

 written at Port of Spain, Trinidad. These paragraphs contain an important 

 contribution to the subject under discussion : 



" At Montevideo, Uruguay, while the ' Newark ' and the ' Detroit ' were at 

 anchor more than two miles from the shore, mosquitoes in considerable numbers 

 were frequently blown on board by the land breeze. I send you a specimen of 

 these mosquitoes, which I caught in my cabin last June. The land breeze which 

 brought them off was moderate in force. [The species proved to be Anopheles 

 annuKpalpis Arrib.] 



" At Uha Grande, Brazil, mosquitoes were blown or flew on board the ships 

 at anchor more than a mile from shore. . . . 



" While the ' Detroit ' was at target practice in June, 1903, off the English 

 Banks, Eiver Plate, nine miles from Flores Island and fourteen or fifteen miles 

 from the mainland of Uruguay, a moderate breeze blew mosquitoes on board in 

 swarms during several days and nights. The insects were most numerous at 

 night. The opposite shore of the river was from sixty to a hundred miles away. 

 These mosquitoes were small, delicate and black colored. Unfortunately no 

 specimen of them was caught and preserved. 



" Lieutenant Commander J. H. Hetherington, U. S. N., states that, while he 

 was attached to the U. S. Coast and Geodetic Steamer ' Gedney ' in the spring 

 of 1884, the ship went out one morning early to take soundings on a shoal to the 

 eastward and southward of Galveston, Texas. Just after anchoring at the shoal 

 about 9 o'clock a. m., a heavy squall of rain passed over the ship from the west- 

 ward. After it had rained hard for a few minutes the weather became clear and 

 warm. As soon as the rain ceased, it was seen that the ship was infested with a 

 dense swarm of large, black or dark looking mosquitoes that were unusually 

 voracious and immediately attacked every one. In a few hours they had entirely 

 disappeared. The ship was at that time about 27 miles from land. 



" The mosquitoes ordinarily noticed on board ship in Galveston Harbor were 

 of a light brown color, and smaller than those which came with the squall above 

 mentioned. 



" Manson states in his work on tropical diseases that ships anchored a mile 

 from shore are safe from infection by mosquitoes. The experience of our ships 



