BOT-FLIES. 209 
they do by throwing off their old skins and replacing them 
with smooth and lancet-shaped new ones.. The nomadic 
males are found not only in the nasal cavity, but also in the 
pharynx anc larynx, while the females are less active. They 
are shown in position in fig. 173. 
Generally speaking this parasite is not as common in 
the United States asitis in Europe. It has been found in 
the nasal cavities of the horse, mule, sheep, goat, hog and 
man. The actual and most natural hosts are the dog and 
the rabbit. If we prevent our dogs from eating the entrails 
of rabbits, sheep, etc., and do not permit them to visit 
slaughter-houses, there is little danger of an infection. To 

Fig. 173.—Three parasites in position in head of dog. 
remove such parasites an injection of dilute ammonia, ben- 
zine, etc., is used; but in case of a valuable animal a veterin- 
ary surgeon should be consulted. Dogs infested rub their 
noses quite often, sneeze frequently, are easily excited, and 
become angry and bite. Ifnumerous in the internal organs 
the parasites may cause death. The mature parasites cause, 
in man, bleeding of the nose, violent catarrh, and intensive 
headaches; those encysted in the liver cause other serious 
disturbances, and if they migrate, bleeding of the lungs, in- 
flammation, and even death. Another species of Five- 
mouths is very common in Egypt, where it is found encysted 
in the livers of negroes. 
Children should never be permitted to kiss dogs! 
Dee ber hrs GALE LES, 
( stride). 
The flies that belong to the above family are only para- 
sitic in their larval state; the inactive pupal state is passed 
