Of Flies . 43 
have the biggefl duller of eyes, in proportion to its 
head, of any other fmall fly; it indining fomething 
towards the make of the large dragon fly, which is the 
moll remarkable of all other infeds for its fine pearled 
eyes. 
The greatell part of the head was nothing elfe but 
two large protuberances, A B. C D E, whofe furface was 
covered over with a multitude of fmall hemifpheres, 
placed with the utmofl: regularity in rows, eroding each 
other in a kind of lattice-work. 
That half of them C D E, C D E, which looked to¬ 
wards its legs, were obferved to be fmaller than the 
other half A B C E, A B C E, which looked upwards and 
Tideways. The furface of thefe hemifpheres were fo ex¬ 
ceeding fmooth and regular, that in each of them Mr. 
Hook was able to difeover a landfcape of thofe things 
which lay before his window, part of which was a 
large tree, whofe trunk and top he plainly faw. Alfa 
the motion of his hand and fingers, it moved netweea 
the object and the light. Thefe rows of eyes was To 
difpofed, that no objed was vikble from his head, but 
Tome of thefe hemifpheres were directed againfl it: and 
further, that where the trunk of the body feem’d to 
hinder the prolped, thefe protuberances were elevated, 
fo that a fly may be truly faid to have an eye every 
way. Thefe little hemifpheres have each of them a 
minute tranfparent lens in the middle, each of which 
hath a diftind branch of the optick newe miniltring 
to it, and rendering it as fo many diftind eyes 3 fo that 
as moft animals are binocular, flies, beetles, &c. are 
multocular, having as many eyes as there are perfora¬ 
tions in their cornea c . By which means as other crea¬ 
tures are obliged to turn their eyes to objeds, thefe 
havs 
e Derham’s Phy. Theo. p. 37 2. 
