RoyalSogietv. 63 
fubllance, which was very thin, and on which it relied as on its 
bafis : Dr. Moulen obferved three pair of nerves in all the broad- 
billed birds, and in all fuch as grope for their food out of fight, 
as ihitts^ woodcocks, curlews, gecfe, ducks, teal, widgeon, ^c, 
thefe nerves are very large, equalling almoft the optic nerve in 
thicJcnefs 3 they begin a little more forwards than the auditory 
nerve from a fmall protuberance, which feems to be made for 
them 5 one of them goes over the optic nerve in the orbit of the 
e ye, the other two go under the eye 5 two are diilributed near 
the extremity of the upper bill, and are there very much expand- 
ed, pairing thro' the bone into the membrane, which lines the 
roof of the mouthy the third pair is diftributed near the end of 
the lower bill, and is fubdivided like the former: Notey that 
birds, that pick their food where they can fee it, have not thele 
nerves, and that the pair of nerves, belonging to the upper bill, is 
confiderably fmaller in proportion to the fowls than thole obferved 
above 5 whence it is probable, that thefe nerves were defigned 
for fome confiderable ule, both on account of their number, and 
their bulk, which is to enable them to diftinguifh their food, 
there being a neceflity of a more exquifite lenie in thefe fowl than 
in any other : All the eyes of fowl and fifli that the doftor had 
ever examined, were more or lefs cartilaginous ^ for the Sclerotis 
i^ 3. csLrtihgcfuf generis i efpecially near the Cornea in all thefe 
animals- and in the larger forts of both, he found the whole 
Sclerotis cartilaginous : In the eyes of fifh he oblerved, that the 
^roceffus Ciliaris is not faftened to the joining of the Cornea and 
Sclerotis, as in all other animals he dilTe^Sed, fo as to hinder the 
aqueous humour to go any farther backwards 3 for he conflantly 
oblerved, that the aqueous humour may move a good way back- 
wards in fome, and in others almolt as far as the optic nerve ; In 
all the fifh he examined, he found a membrane which covered 
the tunica Cornea, fo as to prevent any water coming to it 5 and 
this anlwers the Membrana iiitlitans in fowl, and reaches on all 
fides to the {kin of the fi/li, to which it is faftened 3 it is tranfpa- 
rent and pretty thin, as is alfo the Cornea, if compared with that 
of quadrupeds: He frequently oblerved in irnaller fowl, that the 
membrane of the drum was double 3 for by gently pulling away 
the membrane which lines the tube of the ear, he obferved at the 
bo'itcm of it a tranfparent membrane, which at firll he took to 
be the membrane of the drum, but upon exammation, he found 
that the membrane of the drum was ftill entire, and in its proper 
place 3 he Ibmetimes alfo obferved this in larger fowl, in a leal, 
and in fome otljer animals. 
Ti3e 
