REMOVAL OF INSECTS FROM THE NOSTRIL. 



195 



are recommended for the cure of this disease, but 

 I have decided objections to one and all of them. 

 When the foot is clean, endeavour, by frequent appli- 

 cations of soap and vi^ater, to keep and treat the ulcers 

 as directed in paragraph 1 10. 



(155.) Inflammation produced by Insects in the 

 Air Passages. Much annoyance is caused to the 

 sheep by the presence of animals in the air passages. 

 The CEstrus ovis deposits its eggs on the margin of 

 the nostril in autumn ; these are soon hatched, and the 

 larvae immediately find their way up the interior of the 

 nose, till they arrive at the frontal sinus, a cavity 

 situated between the layers of the frontal bone, and of 

 considerable size in the sheep. Here they remain till 



e following spring, when they quit their hold, become 



nged insects, and enter upon the career of torment 

 !0 ably gone through by their predecessors. 



The Pentastoma, an animal supposed at one time 

 only to exist in the frontal sinus and lungs, and on the 

 surface of the liver, of the dog, wolf, and horse, as well 

 as in some reptiles, has been discovered by an able 

 naturalist, my friend Mr Rhind of Edinburgh, in the 

 frontal sinus of the sheep. It spends its whole existence 

 there, and is distinguished from other entozoa by hav- 

 ing the mouth between two pores on each side, through 

 which a spicular process comes out. Figure 3, Plate 

 VII. is taken from a drawing kindly furnished by Mr 

 Rhind. 



(156.) Removal of Insects from the Nostril. The 

 CEstrus ovis occasions much distress to the sheep at the 

 moment of depositing its eggs within the nostril. The 

 animal on feeing the movements of the fly, rubs its 



