438 Mr. Hunter’s Obfervaticns on the 
that fly to great heights, and move through a confiderable 
fpace, in fearch of food, have their eyes larger in proportion 
to their fize. 
The eyelids have but little motion, and do not confift of 
loofe cellular membrane, as in quadrupeds, but rather of the com- 
mon adipofe membrane of the body ; the connexion, however, 
of their circumference with the common integuments is 
loofe, the cellular membrane being lefs loaded with oil, which 
allows of a flight fold being made upon the furrounding parts 
in opening the eyelids. This is not to an equal degree in them 
all, being lefs fo in the Porpoife than in the Piked Whale. 
The tunica conjunctiva, where it is reflected from the eyelid 
to the eyeball, is perforated all round by fmall orifices of the 
duCts of a circle of glandular bodies lying behind it. 
The lachrymal gland is fmall ; its ufe being fupplied by thofe 
above-mentioned ; and the fecretion from them all, I believe, 
to be a mucus fimilar to what is found in the Turtle and Cro- 
codile. There are neither punCta nor lachrymal duCt, fo that 
the fecretion, whatever it be, is wafhed off into the water. 
The mufcles which open the eyelids are very ffrong : they 
take their origin from the head, round the optic nerve, which 
in 1'ome requires their being very long, and are fo broad as 
almoft to make one circular mufcle round the whole of the 
interior ftraight mufcles of the eye itfelf. They may be di- 
vided into four ; a luperior, an inferior, and one at each 
angle : as they pafs outwards to the eyelids, they diverge and 
become broader, and are inferted into the infide of the eyelids 
almofl: equally all round. They may be termed the dilatorcs of 
the eyelids ; and, before they reach their infertion, give off 
the external ftraight mufcles, which are fmall, and inferted 
into the fclerotic coat before the tranfverfe axis of the eye : 
thefe 
