410 



INSECT ARCHITECTURE. 



sue him. These flies appear sometimes to hide them- 

 selves in the grass, and as the horse stoops to graze 

 they dart upon the mouth or lips, and are always 

 observed to poise themselves during a few seconds 

 in the air, while the egg is preparing on the extended 

 point of the abdomen." * 



The moment the second fly just mentioned touches 

 the nose of a sheep, the animal shakes its head, and 

 strikes the ground violently with its fore-feet, and at 

 the same time, holding its nose to the earth, it runs 

 away, looking about on every side to see if the flies 

 pursue. A sheep will also smell the grass as it goes, 

 lest a fly should be lying in wait, and if one be de- 

 tected, it runs off in terror. As it will not, like a horse 

 or an os, take refuge in the water, it has recourse to a 

 rut or dry dusty road, holding its nose close to the 

 ground, thus rendering it difficult for the fly to get at 

 the nostril. 



When the egg of the ox breeze-fly (Hypoderma 



a, the belly of the grub, b, its back, c, Ihe tuil of the grub, 

 yieatly magnified, ft, the bump, or gall, having its external 

 aperture filled with the tail of the grub. 



* Linn. Trans, iii. 305. 



