PARASITOLOGY. 17 
gauzy wings; antennae composed of fourteen seg- 
ments; three pair of long and slender legs; one 
pair of eyes. 
Life Cycle.—The ova are laid in boat-shaped masses 
on the surface of the water. The larvae are small, 
black, worm-like bodies, with forked tails in which 
are placed the breathing tubes. They are noted to 
come with this end to the surface of the water for 
the purpose of obtaining oxygen. They are found 
in cisterns, ponds and pools of water everywhere, 
and are commonly called wigglers. They pass this 
stage in seven days, if conditions are favorable. 
The pupal stage is passed in twenty-four hours. 
The ova hatch in from sixteen to twenty-four 
hours. 
Animals Attacked.—Among the species that attack 
man and beast are the Culex Pipiens. The Culex 
Equinus especially attacks the horse. The genera 
Anopheles and Stegomia furnish species which attack 
man and communicate the protozoa producing mala- 
ria and yellow fever. 
Parts Intested.—The attack is made upon the skin, 
principally in the evening and at night, by means of 
the stylet of its rostrum. In piercing the skin it 
instills a poison which produces inflammation, itching 
and swelling. 
Prophylactic Treatment.—It has been suggested to 
put fish in the ponds and large bodies of water, to 
consume the larvae. Kerosene, one ounce to each 
fifteen square feet of water, will prevent deposit of 
ova. Cisterns and wells should be kept screened. 
No tin cans or other means of providing pools of 
water should be allowed, in which mosquitoes might 
