[ 21 ] 
all round it, to the right or left 5 then fuppofmg one* 
for Example, begins at the Top, and proceeds to the 
right, every individual Fibre fucceeds the other on 
that Side in both Eyes, till the lad of the one Mufcle.,, 
as it were, delivers over its Office to the next Fibre 
of its neighbouring Mufcle, until the Rotation is 
carry ’d all round as oft as the Perfon pleafeth : Now 
in this rotatory Motion, the oblique Mufcles feem 
to me to have very little Share. 
XXXV. 
Hence it appears, that, in moving the Pupil up- 
wards, downwards, or to either Side, all the Fibres 
of each Mufcle fervingto thefe Motions a£t together 5 
but if any other Motion is required between thefe. 
Part of the Fibres of one may join and aflift Part 
of thofe of its neighbouring Mufcie, in order to 
perform it: And this will further appear, if we do 
but confider, that when, for Example, the Obliquus 
fuperior of either Eye afts, it ferves to incline the 
Eye forwards towards the Nofe, with its Pupil 
downwards 5 and, of confequence, the Pupil of 
the other Eye muft be carried from the Nofe, 
and downwards too 5 which can be done no other 
Way than by the Combination of Part of the Fibres 
of the Ahduttor> with feme of thofe of the De^ 
prejfor next them. 
JL 
XXXVI. 
If, without moving the Head, one would endear 
vour to deferibe a circular Line with the Pupils of 
the 
