ANIMAL GALLS. 415 



be in a condition of great pain and suffering, terrible 

 indeed in the extreme, if its flesh were torn and de- 

 voured by as many large grubs; but there is every 

 appearance that they do not at all afflict, or only afflict 

 it with little pain. For this reason cattle most covered 

 with bumps are not considered by the farmer as in- 

 jured by the presence of the fly, which generally se- 

 lects those in the best condition. 



A fly, evidently of the same family with the pre- 

 ceding, is described in Bruce's Travels, under the 

 name of zimb, as burrowing during its grub state in 

 the hides of the elephant, the rhinoceros, the camel, 

 and cattle. " It resembles," he says, " the gad-fly in 

 England, its motion being more sudden and rapid 

 than that of a bee. There is something peculiar in the 

 sound or buzzing of this insect; it is a jarring noise 

 together with a humming, which as soon as it is 

 heard, all the cattle forsake their food and run 

 wildly about the plain, till they die, worn out with 

 fatigue, fright, and hunger. I have found," he adds, 

 " some of these iubercles upon almost every ele- 

 phant and rhinoceros that I have seen, and attribute 

 them to this cause. When the camel is attacked by 

 this fly, his body, head, and legs, break out into 

 large bosses, which swell, break and putrefy, to the 

 certain destruction of the creature."* That camels 

 die under such symptoms, we do not doubt ; but we 

 should not without more minutely accurate observa- 

 tion trace all this to the breeze-fly. 



MM. Humboldt and Bonpland discovered, in 

 South America, a species probably of the same 

 genus, which attacks man himself The perfect in- 

 sect is about the size of our common house fly, 

 (Musca domestica), and the bump formed by the 

 grub, which is usually on the belly, is similar to that 



* Bruce's Travels, i. 5, and v. 191. 



