T 4 
Mosquitoes and 
in 1878 was the first to suggest and prove the carriage of the 
worms by mosquitoes, though it was not until much later, through 
the researches of Annett, Dutton and Todd (1901), Lebredo (1905) 
and Eulleborn (1908) that the entire life-history was elucidated. 
In this case the parasite, owing to its large size, cannot be intro¬ 
duced directly into the blood while the mosquito is in the act of 
biting, but it has been ascertained that it escapes from the 
mosquito while the latter is so engaged, and afterwards finds its 
own way through the skin of its victim. 
A number of different mosquitoes have been proved to be 
capable of carrying these worms, including Stegomyia fasciata and 
several species of Anopheles, but the chief carrier throughout the 
tropics appears to be the species known as Culex fatigans. This 
is almost exactly like Culex pipiens, the common house-gnat of 
Europe; it is a reddish-brown or dark brown insect, with 
dark legs and five transverse whitish bands on the abdomen. 
Apart from these bands it has no special markings. Like 
the yellow fever mosquito it is domestic, but not quite exclu¬ 
sively so. Like its European relative it bites exclusively 
at night ; and in connection with this habit it is a remark¬ 
able fact that the embryo worms show a definite periodicity, 
coming close under the skin at night and retiring further into 
the body during the day-time. 
THE CONTEOL OE MOSQUITOES. 
Prevention of Bites. —Although not sufficient in itself, it is 
often advisable to supplement other measures by adopting some 
means of preventing the attacks of mosquitoes. Such measures 
are particularly applicable to those with nocturnal habits, and can 
be used with good effect against Anopheles . 
(a) All windows and doors may be covered with a fine wire 
gauze and kept closed from sunset to sunrise, a plan which has 
been largely adopted in Panama ; or the ordinary mosquito curtain 
may be used to protect the sleeper. 
( b ) In addition to the screening methods, and for protection 
against day-flying mosquitoes, such as Stegomyia fasciata, or the 
swarms of sylvan or swamp-breeding species, a variety of sub¬ 
stances have been recommended for rubbing into the skin of the 
