Cavicola. Cephalemyia. CEstrida. 83 



nurus, in attacking all ages, in winter mainly, in sneezing, nasal discharge 

 and expulsion of grubs. Prevention : Keep from coarse tufty pastures, 

 brush ; smear nose with myaicide, tar, from auger holes, holding salt, grow 

 broom, face cover with tar or asafoetida, plow up furrow in field, benzine, 

 sprinkle folds with tar, naphthalin or lime water. Keep clean. Treatment: 

 Sternutatories in first few weeks— quick lime, helebore, snuff, naphthalin, 

 benzine injections. Tobacco smoke, burning tar, fumes. Surgical : re- 

 move horns or trephine sinuses, inject benzine, water, and again benzine. 

 Close wound ; apply tar. CE. Maculata of camel, dromedary and buffalo. 

 CE. Trompe of reindeer. CE. Variolosus. CE. Purpureus. 



CEstrus (Cephalemyia) Ovis. Sheep Gadfly. This is 

 small, about the size of a house fly (10 to 12 mm.) ; yellowish 

 gray, with very short, fine hairs, each set on a small tubercle ; ab- 

 domen in five rings, variegated color ; legs brown ; wings di- 

 aphanous with three dark spots at their ba.se. Eyes purplish 

 brown ; three eyelets on top of the head ; no mouth ; under side 

 of head white. 



This fly attacks sheep and goats in Europe, Asia, Africa, Aus- 

 tralia, the Canary Islands, and North and South America. It is 

 viviparous, and flies from June to October, and, in warm folds 

 where early lambs are raised, for the whole winter, following the 

 sheep and depasiting the grub on the margin of the nostril. By the 

 aid of its hooks the embryo attaches itself and works its way up into 

 the nose. It hibernates in the turbinated bones, but especially in 

 the frontal and maxillary sinuses, remaining there for about ten 

 months, and having attained larval maturity, it passes out into 

 the no.se and is expelled by sneezing. It bores its way one or 

 two inches into the ground, contracts to about half its former .size, 

 becomes a pupa in about two days, and in from three to eight 

 weeks more emerges as a mature fly. 



When deposited on the .skin the larva is about 2 mm. long, and 

 it gradually grows to 20 mm. It has eleven rings, smooth on the 

 dorsal aspect and covered with spines on the ventral, and is fur- 

 nished with two strong buccal hooks. After the first moulting 

 (u.sually in March), it attains a length of 6 mm., and changes 

 from a white to a yellowish shade. After the .second moulting it 

 changes to a deep brown, the integument becoming hard and re- 

 sistant. 



Lesions. These consist, first in the presence of the larvae (i to 

 10 or more), mostly in the frontal sinuses, and in horned sheep 

 in the hollow bony supports of the horns ; in mucopurulent mat- 



