V. 



THE VITREOUS HUMOUR. 

 BY PROFESSOR A. IWANOFF. 



THE vitreous humour occupies the greater part of the cavity of 

 the globe of the eye, and is surrounded posteriorly and laterally 

 by the retina. The anterior surface is hollowed out into a 

 slight fossa, in which lies the lens enclosed by its capsule. It 

 presents a free surface from the margin of the lens to the apices 

 of the ciliary processes, and this part looks towards the zonule 

 of Zinn. The supposed interspace between this free part of the 

 vitreous and the zonule of Zinn is termed the canal of Petit, 

 which surrounds the whole free sequatorial border of the lens. 



The dimensions and relations of this canal during life (canal 

 godronne of Petit) have not been very accurately ascertained. Briicke 

 describes the canal of much smaller size than is in accordance with 

 the original description by Petit. Henke goes still further, and denies 

 generally the presence of such an open space in the living eye. "It 

 is not," he says,* " to be regarded as an open space, any more than the 

 pleura, peritoneum, or articulations ; but, like- them, as a fissure between 

 two free (serous) surfaces, m-oveable over one- another, and without 

 an intermediate space." Henle- holds the same opinions; whilst 

 Kolliker, on the other hand, believes that although, the canal is cer- 

 tainly very narrow, it yet has a distinct lumen in the living eye, and 

 contains a fluid. 



My own researches support th*e view entertained by Henle, as in 

 frozen eyes, at least, I was unable to discover any ice in the canal. 



The vitreous is not, as has been hitherto generally admitted, 

 * Grafe's Archiv, Band vi., Heft ii. } p. 61. 



