chap, iv.i THE ORBIT AND EYE, 43 



free from it. In front it lies under the ocular con- 

 junctiva, with which it is intimately connected, and it 

 ends by blending with that membrane close to the 

 margin of the cornea. Behind it fuses with the sheath 

 of the optic nerve, where the latter pierces the 

 sclerotic. The surface of the membrane towards the 

 globe is smooth, and is connected to the eye-ball by 

 some soft yielding areolar tissue. It thus forms a 

 kind of dome for the globe, a species of socket in 

 which it moves. The posterior surface of the capsule 

 is in contact with the orbital fat. The tendons of the 

 ocular muscles pierce the capsule opposite the equator 

 of the globe. The lips of the openings through which 

 the four recti pass are prolonged backwards upon the 

 muscles, in the form of sheaths, very much as the 

 inf undibuliform fascia is prolonged upon the cord from 

 the internal abdominal ring. Mr. Lockwood points 

 out that each of these four apertures is strengthened 

 by a vertical slip of fibrous tissue, the intracapsular 

 ligament. As the capsule is fixed at various points to 

 the wall of the orbit, these ligaments act as pulleys, 

 and protect the globe from pressure during contrac- 

 tion of the muscles. When the insertions of the 

 recti muscles are divided in cases of strabismus, the 

 capsule is distinctly seen after the conjunctiva has 

 been cut through, and requires also to be divided 

 before the section of the muscle can be properly made. 

 The capsule is of some importance in this procedure. 

 After its division, the muscle does not entirely 

 retract and lie shrunken within the orbit. Its con- 

 nections with the capsule still give it some hold upon 

 the globe, and still enable it to act \ipon that struc- 

 ture. Moreover, the attachments of the capsule to 

 the margins of the orbit prevent the muscles from 

 entirely retracting, and, even when the globe has been 

 removed, they give them some basis to act upon, and 

 thus tend to preserve some little mobility in the stump. 



