112 



THE KEPOET OE THE 



No. 36 



after the first one left, but soon went through the same antics as the first. Both 

 calves ran erratically about the paddock; they finally discovered a barrel used 

 for watering the cattle; they both tried to get into it at once, and I was fortunate 

 in securing a photograph of them in this position. 



The flies (there were, I should judge, three or four in the field) kept on 

 striking even when they were in the barrel. Later the calves found a corner 

 behind some boards, there they lay perfectly quiet with their noses stretched 

 out straight in front of them on the ground. Occasionally a fly would find them, 

 they could stand the fly striking perhaps half a dozen times, but then, suddenly, 

 they Avould get up and run as if possessed. 



I have noticed the cows endeavoring to hide from the. flies just in the same 

 way. If they could find the least bit of shade along a fence or building, they 

 would lie there quite motionless, until roused by the repeated attacks of the fly. 

 In some cases cattle lie down also from exhaustion. 



This experiment was also witnessed by Mr. Moore. 



Calves attacked by Hypoderma tovis 

 trying to get into a barrel of water. 



Hypoderma hovis sitting on fence, 

 waiting to attack cattle. 



In my first paper of 1912, I gave my reasons for cattle being afraid of 

 H. hovis. I quote the following : " It is this clumsy, persistent attack which I 

 believe frightens cattle, and I would suggest that probably it is this cause which 

 makes cattle stampede or ' gad.' When the Tabanidce (or other flies) attack an 

 animal and cause anno5''ance, the cow simply flicks her tail or brushes off the fly 

 with her tongue, and feels that she has control or can get away from the insect. 

 But a Warble fly comes buzzing along, strikes a time or two, and when the animal 

 it is attacking kicks or stamps, it c^mes back just the same. Then the animal 

 begins to lose its head and runs away, and when it still flnds itself followed 

 becomes wild with terror." 



There have been so many false theories advanced for the fear which these 

 flies engender, that I feel licensed to go fully into this question. 



The commonest theory is that cattle are afraid of the fly because of its 

 resemblance to a bee. The experiment just quoted refutes this entirely, because 

 the calves had never seen a bee. Another idea is that cattle fear the fly because 

 they are aware that it will cause them future trouble. This idea must have 

 come from someone who thought that cattle were endowed with especial intel- 

 ligence. 



