On the multitude of eyes or optical organs in the eye of a Beetle. 

 The optic nerves of each of the optical organs in the eye of a 

 large Fly, particularly dejcribed : aljo the brain of a Gnat ; and 

 the nature and probable ufe of the hairs on the feet of Flies 

 and Crab-ffh. 



X HAVE formerly made mention of the great number of optical 

 organs, or eyes, with which fmall flying animals, such as the 

 dragon-fly,* or libella, the common fly, and others, are furniflied ; 

 and I have often fliewn thofe eyes to fome curious gentlemen, 

 when they came to vifit me, to their great delight, particularly 

 when they found that obje<5ls ipight, with the greatefl: clearnefs, be 

 difcerned through each of thofe optical organs, to the number 

 of feveral hundreds at a time. 



Among other inftances, I, upon a certain occafion, exhibited 

 to feveral Englifli gentlemen of rank, the great number of optical 

 organs which are found on the tunica cornea, or horny part of 

 a Beetle's eye; at which fight thofe gentlemen were aftoniflied, 

 and the rather, as it is a kind of proverbial expreflion in England, 

 when they would reproach any perfon with blindnefs or fl;upidity, 

 to fay, " He is as blind as a Beetle," under a notion that that animal 

 is void of fight. 



With regard to this creature, I began " by feparating from 

 the head that part which is commonly called its eye, and, having 

 cleared away the blood veflels, and other matter adhering to it, 

 I placed it before the microfcope, and then I faw that the protuber- 

 ance, or rifing of this eye, was not a perfed hemifphere, being 

 rather more extended in length than in breadth. 



* This creature is vulgarly called, particularly by children, an horfe-flinger ; but Tery 

 erroneoufly, for it has not a fting, nor any weapon of offence, that is discoterable by us. 



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