MOSQUITOES ON BOARD SHIP 349 
openings none were found. Iron water tanks, as a rule, are more securely 
covered and are given more attention than the wooden containers. The two or 
three barrels, placed in front of the galley and forecastle, are more frequently 
infested and in every instance perference was given them in the examination. 
The box of the carpenter’s grindstone offers another favorite place for the 
breeding of this insect. An examination of the cabins was made to determine 
the presence or absence of adult insects. In the room from which the man 
with yellow fever was taken, the insects were found in abundance, both normal 
and blood fed, resting in the shady corners on dark objects hanging around the 
room. Considerable effort is necessary to detect mosquitoes when they are few in 
number ; each cabin should be gone over systematically, passing the hands in the 
corners and gently shaking the hanging articles until every object above the 
floor has been gently disturbed. The forecastle and galley of this schooner, 
immediately behind the breeding barrels, harbored the insect in abundance. 
“The steamship William Cliff is of interest in connection with the trans- 
ference of mosquitoes by vessels as well as furnishing data relative to the period 
of incubation and spread of malaria among a crew where all outside influences 
were removed. 
“This vessel sailed from Liverpool, England, on May 29, 1902, with the fol- 
lowing itinerary : 
Arrived. Port. Sailed. 
JUNC: Wess sccviccawe< as St. Thomasisicci.ncsaeees sos eeds June 12 
SUNG: LO ec Petraes dace e COLO he i sesh eonideeSoverenace peaesauaiaepakd dunes June 16 
TUBS: 19). 5s asecancarcnesa aie os RATE STON: wcceineccsce ceed a aare ied wiaresd June 20 
TUNG: 2553 scerseswcascasinoeanstaveraie PRAM DLCO:. aijicsites -scsaies ciedcdtesae sive sre June 26 
JUNC 21 03s taseewacuiee s Vera: Crudinsicsssceaie coseen sawaneces July 1 
“Until arrived in Tampico no sickness had occurred on board; while leaving 
that port one man was taken sick with a vague chill, and illy defined pains. Two 
days later, June 28, four of the crew were taken sick with pronounced chills, 
pains in the head, extremities, and back, and high fever. The following day, 
June 29, four more including the captain, were taken sick in like manner; on 
June 30, two more were taken sick. 
“On June 29, the blood of two of the cases was examined for the plasmodium 
malaria with negative results. Their absence was accounted for by the large 
doses of quinine administered prior to the examination. On July 1, two new 
cases were examined; in one the tertian parasite was obtained, the other was 
negative. 
“The disease clinically was of the tertian type, about half-intermittent, the 
balance remittant. All, with one exception, responded readily to quinine. The 
exception resisted the quinine for three days. An examination of the ship was 
made to determine the genera and species of mosquitoes on board. Of these 
there were three genera and four species in abundance, as follows: 
“Anopheles argyrotarsis, Culex fatigans, Culex tentorhynchus, Janthinosoma 
Lutz. 
“ All the varieties mentioned were found in the forecastle and after wheel- 
house, the crew’s quarters being aft instead of forward. The cabins failed to 
show the presence of mosquitoes on the examination of June 30, nor were any 
noted previous to that time. : 
“ Anopheles argyrotarsis were present in Vera Cruz, though in very small 
numbers; so scarce, that up to that time only one specimen had been taken. 
This mosquito is also native to Tampico and Colon. According to the history 
of the crew, which on such subjects is very unreliable, they stated that while at 
Tampico they had not been molested by mosquitoes, while at Colon all hands 
suffered severely from bites. The character of the fever is extremely suggestive 
