1168 THE SUSPENSORY LIGAMENT. [BOOK m. 



inelastic membrane, the suspensory ligament (Fig. 134) is attached 

 to and becomes fused with the capsule of the lens on the anterior 

 surface of that body. 



During life the vitreous humour is in contact not only with the 

 posterior surface of the lens, but also with the back surface of the 

 suspensory ligament. After death, however, through changes in 

 the vitreous humour, a space is developed, of a triangular form in 

 section, between the suspensory ligament in front, the lens on the 

 inside and the vitreous humour behind ; this is often spoken of as 

 the canal of Petit. According to some authors this canal exists 

 during life and possesses a hind wall which is furnished by a 

 membrane, distinct from the hyaloid membrane or suspensory 

 ligament, which defines the front of the vitreous humour; and 

 if, as asserted, the capsule of the lens be imperfect behind ( 719), 

 something of the nature of a membrane must exist in the 

 front of the vitreous humour, since, when the lens is, in ex 

 traction of cataract, removed from the capsule, the vitreous 

 humour does not escape into the vacant cavity. Since the 

 suspensory ligament is attached on the outside, alternately to a 

 projecting ciliary fold and to the depression between that and the 

 next fold, the canal of Petit, when distended with air by blowing 

 into it, has a beaded appearance. When the canal is thus blown 

 out the suspensory ligament and its attachments are rendered very 

 obvious ; the ring thus formed by the suspensory ligament around 

 the lens is sometimes called the zonule of Zinn. 



We shall deal with the aqueous humour in speaking of the 

 lymphatics of the eye. 



