176 The Marquis Di Spineto on the Zimb of Bruce, 



those of the Bombylius. Its hody, though apparently like 

 that of a bee, is shorter and thicker than that of the Bombylius, 

 which is slender; but it is larger than that of the (Estrus, 

 which is small, and, like it, is covered with a thick brown down, 

 which in the Bombylius is yellow. Its wings are throughout 

 transparent, while those of the Bombylius are more so next to the 

 anterior, but less so towards the posterior margin. It has 

 six legs; they are rather thick and of a bright colour, not so 

 long as those of the Tabanus or of the Bombylius, which are 

 slender and black, but quite as long as those of the CEslrus 

 and the bee. It has no sting, and its motions are more rapid 

 and sudden than those of a bee, and not dissimilar to those 

 of the (Est) us. In flying it makes a sort of buzzing or jarring 

 noise, like the Tabanus and the (Estrus, together with a hum- 

 ming like a bee: this, Mr. Bruce observes, proceeds in great 

 measure from a vibration made with the three hairs at its 

 snout 



It is to be lamented that Mr. Bruce, in giving the short de- 

 scription he has of this insect, has neglected to observe the 

 use to which the three hairs are destined. That they are 

 piercers there is not the least doubt, and most probably per- 

 form the office of suckers, simply because it seems that it 

 does not lay its eggs in the flesh of animals ; for, according to 

 the account which Bruce gives of the evils attending the at- 

 tacks of this fly, the bosses which are produced swell, break 

 and putrify, to the certain destruction of the animal, but never 

 exhibit any larvae or maggots; and in this respect also it differs 

 considerably from the (Estrus, for according to the excellent 

 essay of Mr. Clark, on the Bots of Horses and other Animals, 

 the (Estrus does not pierce the skin of the animal, but only 

 glues its eggs to it, an operation which it performs in a few 

 seconds, during which the animal attempts to lash it off", as 

 it does other flies, with its tail; an evident proof that this in- 

 fliction is not attended with much pain, though after it the 

 animal may be seized with a kind of phrensy; while the very 

 sound of the Zimb terrifies whole herds. Add to this that the 

 larva? of the (Estrus live in wood, which does not seem to be 

 the case with the Zimb, for the country in^which it lives is 

 for miles deprived of wood, though it cannot be denied that 

 there may be sufficient underwood to harbour them. 



Mr. Kirby, who copies the whole account given by Bruce, 

 considers this fly, both from its habits and figure, to belong to 

 the Tabanidce, and thinks it congenerous with the (Estrus of the 

 Greeks. He has, no doubt, adopted this opinion on the autho- 

 rity of Mr. W.S. MacLeay, who, in a learned paper published 

 by the Linnsean Society, has shown, that " the /x-uwj/ and the 



