PARASITES OF THE RESPIRATORY TRACT 107 
then moult and develop rings, each ring bearing a 
number of short spines. At this stage the parasite is 
spoken of as Linguatula denticulatum. 
They remain encysted for about six months, and then 
migrate into the peritoneal cavity, pleura, or intestine, 
and escape into the open. Occasion- 
ally they bore into a bronchus and 
are coughed up. 
Dogs may be infected by sniffing up 
larve thus deposited on the ground, 
or by ingesting rabbits, or portions of 
viscera containing larve. 
SymMPToMs, ETc.—The adult parasite 
is found between the turbinated bones 
or in the frontal sinus of dogs, or 
occasionally of goats, sheep, or even 
man. 
The symptoms consist of unilateral 
nasal discharge, sneezing, epistaxis, 
dyspnoea, and coughing. 
TREATMENT. — Injections of weak 
creolin, lysol, or iodine solutions. 
Inhalations of chloroform, carbolic 
acid, turpentine, sulphur, iodine, for- 
malin, etc. 
Larve of Céstrus Ovis.—The fly 
which represents the adult form of 
this larva is from Io to 12 millimetres in 
length, with a yellow head, a brownish- 
grey thorax, and an abdomen mottled 
with white, yellow, and black. The 
wings are transparent, and show a terminal streak and 
three spots. The fly is active from May to October. The 
female lays her eggs in, or close to, the nostrils of a sheep. 
Sheep, when attacked by the fly, rush wildly about, and 
rub their noses against trees and fences until they bleed. 
Fic. 29.—LinGua- 
TULA TANIOIDES, 
