s. HOLTH AND O. BERNER. M.-N. Kl. 



bryonal stage; or the rudiments may perhaps have been moved to a wrong 

 place too near to the iris. I will not venture to give any opinion on this 

 question ; it requires still further material before it can be answered. It will 

 be interesting to see whether corresponding conditions will be found in 

 future cases of congenital miosis. 



In this connection I may mention that on going through my numerous 

 single sections from the irides of the twin sister, Anna B., I have found 

 in a few places analogous "thickenings" near the periphery of the iris. 



It will be remembered that single sections of material embedded in 

 celloidin formed the basis of my investigation of the twin sister's eyes. It 

 was not until towards the end of my work that I thought of bleaching 

 the whole iris and embedding it in paraftin, and this, I should think, is the 

 reason for my having o\'erlooked the fact that in her eyes, too, there were 

 these "projections", although not so numerous as in the brother's eyes. 

 From the material I still had left from the sister's eyes, I made some series 

 after previous bleaching, and found two or three such places there too. 

 They were situated in about the same place as in the brother's eyes, perhaps 

 a little more peripherally. In one of them I found that the epithelium had 

 turned into the "projection" in such a degree that it made a large hollow, 

 the wall of which was covered in front by a thick layer of muscle. 



It will probably be apparent from the above description that I have 

 always found that the "projections" are associated with other formations, 

 which can onl}' be explained as due to developmental anomalies. Among 

 these anomalies I will direct attention to the thick mass of muscle that is 

 shown in hg. 17, which above looks like a band of muscle pushing into 

 the stroma, but which outwards towards the ciliary processes resembles not 

 a little the club-shaped swelling in fig. 12. All the transitional stages in 

 the development of these formations are also found. A few sections farther 

 on in the series, the muscle in fig. 17 assumed the appearance of a typical 

 "hook", such as is seen in fig. 16. We should therefore be justified in 

 regarding them as various stages or forms of a single developmental ano- 

 maly. They are certainly most nearl}^ allied to the strengthening apparatus 

 that Heerfordt and Forsmark have described. Klinge has also made 

 them the subject of a comparative examination, but he has found that the 

 fillets that Heerfordt and Grynfeltt have described as occurring in animals 

 with a poivcrfitl dilatator pupillae, are just what occur in those that have 

 a poorly developed dilatator. Where they are found in my material, they 

 seem undoubtedly to be the expression of Nature's desire to make up tor 

 her neglect in letting the peripheral zone of the iris be without dilatator. 



As regards the relations between the dilatator and the sphincter I have 

 little to add to what I found on examination of the sister's eyes, and there- 

 fore refer the reader to my previous paper. It is evident from the rather 

 numerous in-drawings of the epithelium of the iris (one of which is shown 

 in fig. 19) that in this case, too, the sphincter has exerted a strong pull 



