MOSQUITOES AND VESSELS 351 
variety, where and when they came aboard, and under what conditions. 
Gulf Quarantine Station is an especially good point for these observations, 
from the fact that it is 10 miles from the mainland, and because vessels bound 
here do not pass near land, and so but rarely take on mosquitoes en route, and 
even these, as will be seen, are always the marsh-bred varieties of Culea. Be- 
sides, the examination of at least a thousand mosquitoes on Ship Island has 
convinced me that there are no Stegomyia here. 
“ Each vessel inspected was carefully searched, the inspector being armed 
with a cyanide killing bottle, and in addition the captain was asked the following 
questions : 
sae Ie i pete any mosquitoes on board on your outward voyage, consisting 
ays! 
“2. If so, did they come aboard before departure from home port or at sea, 
and under what circumstances ? 
“3, Were there any mosquitoes on board at your destination or on homeward 
voyage ? 
“4, If in port— 
(a) How far were you from shore? 
(b) Prevailing wind and weather? 
“5. If on homeward voyage (consisting of 
(a) Were they from port? 
(b) He hey come aboard at sea, on what day, and how far were you from 
and! 
(c) Were there wigglers in any of your tanks at any time? 
“ During the five months from June 1 to November 1 observations were made 
on 82 vessels, all arriving from ports where the Stegomyia is believed to exist 
in quantities. Of these 78 were sailing vessels and 4 were steamers. 
“Of these 82 vessels, 65 claimed to have had no mosquitoes aboard at any 
time during the voyage or at port of departure, and their absence having been 
confirmed by search, we can dismiss them from consideration and pass to the 
remaining 17. 
“ Five of these had mosquitoes on board at their ports of departure, 2 being 
rid of them as soon as they were well at sea, while 3 others carried them two days 
and were then no more troubled, except one schooner on which they reappeared 
in quantities five days before she reached port, when she was 20 miles from shore. 
“ Nine sailing vessels, having no mosquitoes on board before sailing, had them 
appear at sea, in one case from the water casks in which the captain found larve. 
But in the other cases they doubtless came from land which was at the time 
distant—20 miles in one case, 15 miles in three cases, 10 miles in one case, and 
2 miles in the last two instances. In all these vessels the mosquitoes found on 
board on arrival at this station were the common varieties of Culex, there being 
no Anopheles or Stegomyia among them. 
“ Stegomyia fasciata were found on board and were identified in the remain- 
ing three cases, as follows: 
“The schooner Susie B. Dantzler arrived from Vera Cruz, Mexico, on July 
16, 1902, after a voyage of fifteen days. The captain stated that mosquitoes 
came aboard in large quantities at Vera Cruz, although he lay a half mile from 
shore and there were variable winds with squalls and rain all the time. The 
number of the insects decreased on the voyage but were always in evidence, and 
we caught four or five of them here. No larve were found in any of the tanks, 
and as the captain had repeatedly examined them without result in his efforts 
to be rid of the mosquitoes, I believe the insects found on board here came all 
the way from Vera Cruz. 
amined to ascertain if mosquitoes were present on board, and, if present, their 
of 
days) — 
