Cavicola. Cephalemyia. CEstridce. 85 



tient walks it may lift the feet high as if travelling in water, or it 

 maj' move unsteadily or stagger, and even fall. These symptoms 

 usually herald an early death, from the third to the eighth day 

 after their onset. 



But in the great majority of cases, with a few larvae only in the 

 sinuses the disease is not fatal, and no symptoms are noticed be- 

 yond nasal discharge, perhaps bloody, and some loss of condition. 



But even these mild cases may become redoubtable in connec- 

 tion with the glare of the sun from a stretch of snow, or water, or 

 in debilitated or asthenic subjects that have been sick from other 

 causes, or from close confinement indoors in winter. 



Diagnosis from coenurus cerebralis is made by the facts that the 

 latter rarely occurs except in lambs or yearlings, that it is not 

 associated with nasal discharge nor sneezing, that it shows no 

 tendency to rubbing of the face, and that no grubs are discharged 

 from the nose. The appearance of the .symptoms in spring or 

 early summer points directly to grub in the head. 



Prevention. Keep sheep away from infested, coarse, shrubby 

 pastures from June to October. If this is impossible apply upon 

 the nose articles which repel the fly. Place a log in the pasture 

 bored full of augur holes 2 J^ inches in diameter and 4 or 5 inches 

 deep, and feed the salt from these holes, the margins and walls of 

 which are kept smeared with tar, or better, a mixture of tar and 

 lard. In this way the sheep are daily dressed without trouble, 

 and the flies are kept at a distance. If all could be compulsorily 

 dealt with in this way the pest could soon be eradicated from a 

 country. When goats are present they must partake of the treat- 

 ment. Some flockmasters believe that the English broom 

 (cytisus Scoparius) in the pastures protects the sheep against the 

 fly. Crude tar, or a mixture of tar and oil, may be smeared on 

 the nose with a brush every few days from June to October. 

 Some use a canvas face cover smeared with tar and lard, or asa- 

 fcetida and lard during the same months. Others plow up a fur- 

 row at intervals in the pasture in which the sheep may poke its 

 no.se when attacked. In a small flock many of the young larvae 

 may be killed by a weekly or more frequent treatment with ben- 

 zine, a teaspoonful in each nasal chamber, the sheep having been 

 turned upon its side to be treated, and the head held nearly level. 

 The soft young grub is more easily destroyed than the older case- 



