68 Veterinary Medicine. 



washed over the head this is not probable. Newly shorn sheep 

 may be passed through the bath more quickly, but those with 

 heavy fleeces may require one, two or even three minutes of active 

 manipulation to saturate the whole mass. In this way the para- 

 site may be permanently eradicated from a flock of even long 

 wooled sheep. To prevent its introduction anew it is important 

 to keep them well apart from other sheep and the places where 

 they have been within a few weeks. Newly bought sheep, those 

 that have been carried in cars or other public conveyance, that 

 have been in public stock yards, on highways traversed by sheep, 

 or at public exhibitions should be dealt with like infested animals 

 and dipped or freely sprinkled in sheds of the wool with insect 

 powder or naphthalin. 



CESTRID^ I,ARV^. GAD-FLIES. EOT FLIES. 



Hibernate as larva in animals: characters of fly, of larva, of nympha. 

 Gastricola, larva in alimentary canal : Cavicola, larva in nasal sinuses : 

 Cuticola (hypoderma) larva under skin or in interm.uscular tissue. 

 CEstrus equi : 6 to 7 lines, body hairy, yellow brown, abdomen reddish, 

 black spots, wing transverse black band, and spots at tip. Distribution 

 America, Europe, Asia, Africa. Ovipositor. Ova glued to long hairs of 

 legs or shoulders of solipeds. Button on closed end glued to hair, open end 

 pendent. Hatched in 24 hours, embryo taken in by tongue or falls on food. 

 Two cephalic hooks fix it to gastric mucosa. Three moultings and stages 

 of growth. Has 12 rings all spined except the two last. Pass out May to 

 October, and in manure or earth form nympha in 24 hours. In 30 days the 

 fly escapes. CEstrus hamorrhoidalis : fly 4 lines, hairy, olive gray with 

 median black band, abdomen first white, then black, at end red, wings spot- 

 less. Distribution : N. America, Europe. Ova black, stuck to long hairs 

 of lip, licked in, or falls in food (manger). Larva moults 3 times becom- 

 ing 6 to 7 lines, greenish, spined except on the two last rings and the mid- 

 dle of the third last. May hibernate in left or right gastric sac, duodenum 

 or pharynx. Hook on to intestines when passing out, and even to skin of 

 anus. Spend 30 days as nympha, then form perfect fly. CEstrus pecorum : 

 Fly 5 to 6 lines, black or brownish, with short smoky wings. Ova black on 

 shoulder and fore limbs. Larva has 3 moultings, attain 5 or 6 lines, each 

 ring has double row of spines, absent from dorsal centre from the fifth, and 

 entirely absent behind the eighth, except on venter. Spend 30 days as 

 nympha, CE. Nasalis: Fly 4 to 5^ lines, thorax golden, abdomen in 

 bands of white, black, yellow and gray, wings short translucent. Ova 

 white, stuck to hairs on nose and lips. Larva 5 to 6 lines, rings spined 



