173 
Mr. Bell on the motions of the eye, .&c. 
they embrace the eye-ball, one passing over it obliquely, the 
other under it obliquely. 
That the recti muscles perform the office of directing the 
axis of the eye, turning it round to every point in the sphere 
of vision, there are many proofs. In the first place, their 
origin, course, and insertion, accurately fit them for this 
office ; and they are obviously equal to it, unassisted by other 
muscles. In the next place, from man down to the cuttle-fish, 
the voluntary motions of the eyes are the same, and the origin, 
course, and insertion of these muscles are similar, while the 
other muscles vary with the change of apparatus which is 
around the eye. 
The oblique muscles of the eye stand contrasted with the 
recti in every respect, in number, size, and direction. Yet it 
is a received opinion, that they antagonize the recti, and keep 
the eye suspended. To this opinion there are many objec- 
tions. 1. In creatures where the eye is socketed on a cup of 
cartilage and cannot retract, the oblique muscles are never- 
theless present. 2. Where a powerful retractor muscle is 
bestowed in addition to the recti muscles, the oblique muscles 
have no additional magnitude given to them. 3. In matter 
of fact, the human eye cannot be retracted by the united action 
of the recti as we see quadrupeds draw in their eyes, which 
is an argument against these muscles being retractors, and 
therefore against the obliqui being their opponents, to draw 
it forward. 
To these, other objections, no less strong, may be added. 
We have just found that certain very rapid motions are to be 
performed by the eyeball ; now it can be demonstrated, that 
a body will be moved in less time by a muscle 'which is 
