ftir the Wings. And when the Feet are in aftion, the 
Wings are quiet, and in their turn ferve to fupport the 
Tendons which dired theFeet. 
After having confidered the ftrufture of all thefe 
Mufcles, we ought to examine thofe of the Eyes, 
wherein there is (bmething which deferves the attenti- 
on of the Curious. They are like two thick oblong 
Pearls, which begin at the fore- part of the Head and 
end in the hinder part Their outer Membrane is dry, 
thin, tranfparent, and inclofe a fraall foft Ball, filled 
with a very black Liquor, two fmall Canals filled with 
Air, enter into each of thefe Eyes, and run along to 
the great Channel, alfo furnifti'd with air, which ac- 
companies the Inteftine from the Head to the Tail 5 
to difcover them without trouble, if we (hould leave a 
LihelU dead for fome days, the internal parts will pu- 
trify and come to nothing, but the Canals will remain 
entire, and as folid and firm as they were before. 
This ftrufture made meat firft think that the LibelU 
could drive the Air contained in thefe Canals into the 
Eyes, to give it a greater convexity to behold objefts 
that are very near, and on the contrary the Air is forced 
out of the Eyes again, to flatten them when they look 
at remote objects 5 and myconjedure is not altogether 
frivolous, for hkving blown into the thick Canals 
which are about the middle of the Body, the Eyes be- 
came confiderably tumified, and by letting the air re- 
turn they became flat again. I fhall fome time fend 
you the parts ferving to Generation of this Animal — 
Till then I am, 
SIR, 
Tonr mojl humhle^ and 
mo(l ohedknt Servant, 
Poupart. 
V. Part 
