82 Veterinary Medicine. 



be nothing unreasonable in making it obligatory on all stock- 

 owners. They may be killed in their sacs by the insertion of a 

 lancet, or a red hot wire, or by injecting benzine, carbolic acid, 

 oil of turpentine or oil of tar, but the decomposing larva remains 

 as a source of irritation and infection. 



In some parts of Europe the cattle are held indoors until tfen 

 o'clock every morning, from April to August, so that the larvae 

 (which habitually escape before this hour) may fall on the paved 

 floor and perish for lack of a shelter in which to pass the stage of 

 pupa. 



In England the flies are driven off by agents smeared on the 

 backs of the cattle. Crude pine tar smeared on the shoulders is 

 very effective, requiring only two applications in a season. Equal 

 parts of tar and oil mixed, is equally effectual but less permanent. 

 Sulphur ointment ; sulphur, oil of tar and oil ; naphthalin ; creo- 

 lin, and other myiacides will act well, but for a shorter time. 



These last named agents would be specially applicable to horse 

 and sheep where tar would be hurtful to wool or harness. 



CAVlCOIvA (cavum cavity, colere to inhabit). CEPHALE- 

 MYIA (cephale head, myia fly). CESTRID.^ HIBERNAT- 

 ING IN NASAL SINUSES. 



ffi. Ovis: Like house fly ; lo to 12 mm. long ; yellow gray ; hairy ; ab- 

 domen variegated. Distribution : Europe, Asia, Africa, America. Vivipa- 

 rous. Flies May to October ; in warm folds all winter ; lodges the embryo 

 on margin of nostrils ; latter enters nose ; turbinated bones, and sinuses ; 

 hibernates, escapes in 10 months, forms pupa in ground and in 3 to 8 weeks 

 the perfect iiy. Larva : 2 mm., grows to 20 mm. ; with n rings, smooth 

 dorsally, spined ventrally ; 2 buccal hooks ; 2 moultings. Lesions : Larva, 

 and exuvia, mucopurulent discharge, congestion of pituita and even cere- 

 bral meninges. Symptoms : Fly darts on nose leaving the grub ; sheep 

 starts, snorts, shakes head, stamps, rushes off with nose to the ground, 

 seeks a rut, road, furrow, or sheep collect in mass, heads in and nose to 

 ground. Attacks in heat of day. Clear, purulent or bloody discharge from 

 the nose, sneezing, rubbing face, shaking head, swollen nostrils or inter- 

 maxillary space, snuffling, hurried breathing, diarrhoea, congested, watery 

 eyes, rolling eyes, dilated insensible pupils, dulness, prostration, inappe- 

 tance, emaciation, grinding teeth, salivation, high stepping, staggering, 

 death. A few larva often harmless ; many deadly. Aggravated by glare of 

 sun, debility, septic infection, close confinement. Diagnosis: From cce- 



