404 CHIKANOSUKE OGAWA 



Effect of turning up of the upper iris edge 



When the lens regenerates from the iris edge, the lens fibers are 

 formed always from the posterior wall of the lens vesicle. This led 

 Wachs to assume that the direction of the lens fibers is determined 

 by the presence of the retina. To examine how far this assump- 

 tion is true, the iris edge was intentionally turned up, in such a way 

 that the upper iris was cut at both sides and turned up in front of 

 or behind the iris. Fifteen specimens were operated upon. In 

 many cases, the bent iris did not remain in place, but came back 

 to the original position, starting normal lens regeneration. Five 

 cases disclosed some variations. 



A. Thirteen days after operation. The iris has been only 

 partially turned backwards, the lens vesicle accordingly was 

 partially turned backward. 



B. Sixteen days after operation. The lens vesicle regenerated 

 from the iris edge posteriorly and slightly dorsally, without taking 

 the normal downward direction, so that the lens fibers run as a 

 whole from above downward posterio-anteriorly. 



C. Eighteen days after operation. The iris had been turned 

 up anteriorly. No typical regeneration was obtained except 

 slight depigmentation and grouping of cells at the edge. 



D. Twenty-one days after operation. The iris was shortened. 

 From the edge a relatively flat lens was formed. The lens fibers 

 run as a whole slightly from above downward postero-anteriorly. 



E. Twenty- three days after operation. Double lenses were 

 formed. One is normal; the other quite abnormal and projects 

 into the anterior chamber from the upper part of the former, the 

 two lenses being partially continuous. A piece of the iris is at- 

 tached behind the lens. The iris may have been severed by the 

 operation in this case. 



If the retina alone determines the direction of the lens fibers, 

 the latter, whatever position the lens may take, must maintain as 

 a whole a sagittal direction, because the retinal influence should 

 remain the same. However, in the above cases the lens fibers 



