Bui. 597, U. S. Dept. of Agriculture. 



Plate IV. 



Secondary Injury from Bot Flies. 



Upper.— Horses rubbing following ovipositions of Gastrophilus haemorrhoidalis. Lower.— Lower 

 lip of horse showing barbed wire cut at the lower extremity which resulted from rubbing. 

 The small holes are injury from the grass Hordeum jubatum. (Original.) 



