NERVOUS SYSTEM. 



other two, for the same reason, are called oblique. With the 

 exception of the inferior oblique, they all arise from the bottom 

 of the orbit., 



1. The Reetus Oculi Superior, being placed immediately be- 

 low the levator palpebrse, arises from the superior margin of 

 the optic foramen. It runs forward, increasing somewhat in 

 breadth, and is inserted by a broad thin tendon into the scle- 

 rotica, two lines from the cornea. 



It turns the eye upwards. 



2. The Reetus Oculi Externus arises from the external mar- 

 gin of the optic foramen. It then advances along the middle of 

 the external wall of the orbit, near the periosteum, to which it 

 adheres slightly, and is finally, inserted, by a thin broad tendon, 

 into the external side of the sclerotica, about two or three lines 

 from the cornea. 



It abducts the eye, or turns it outwards. 



3. The Reetus Oculi Inferior arises also from the optic fora- 

 men, at its inferior margin, and, lying upon the floor of the or- 

 bit as it advances forwards; it is inserted, tendinous, into the 

 under surface of the sclerotica, two lines from the cornea. 



It depresses the eye, or turns it downwards. 



4. The Reetus Oculi Internus arises from the internal mar- 

 gin of the optic foramen, and goes forwards along the internal 

 wall of the orbit, being separated from it by a layer of adipose 

 matter. It is inserted, by a tendinous expansion, into the inner 

 side of the sclerotica, two or three lines from the cornea. 



I.t adducts the eye, or turns it inwards. 



5. The Obliquus Oculi Superior is placed along the upper in- 

 ternal angle of the orbit. It arises from the corresponding 

 margin of the optic foramen, by a small round tendon; it then 

 advances forwards, and when it has got near the margin of the 

 orbit, it is converted into a long round tendon. 



The tendon passes through a cartilaginous loop which is, 

 formed for it, just at the inner margin of the supra orbitary fo- 

 and is connected to the loop by long loose cellular 



