1922. No. 4- MIOSIS CONGENITA SEU MICROCORIA FAMILIARIS. 23 



The great question, as concerns this muscle, is in what way the ante- 

 rior part — the membrane of Bruch — has originated. Has it been by 

 a complete fusion of the contractile parts of the dilatator elements, as the 

 French writer. Grynfeltt, maintains, or are there, in the Bruch's mem- 

 brane, parts that can be isolated so that each belongs to a separate dilatator 

 cell? The latter stand-point is held, as we know, by the Danish author, 

 Heerfordt, who declares that, like Henle, Ivanoff and Merkel, he has 

 isolated the separate cells. Grynfeltt says that sometimes the membrane 

 of Bruch looks as if it were divided up into small fields that might answer 

 to smooth fibres cut transversely. This division is especially distinct in 

 the fox, but even in this animal Grynfeltt has not succeeded in isolating 

 single cells. He never obtained anything but irregular fragments. 



Heerfordt succeeded, however, in isolating the elements in material 

 from the calf and rabbit that were fixed with Müller's fluid, but he has 

 not isolated the cells from human material because, he says, the material 

 he had to work upon was fixed with formol. 



The Swedish investigator, Forsmark, says that he has not succeeded 

 in isolating the elements, but he is nevertheless a supporter of Heerfordt's 

 theory. He believes that the dilatator elements are probabh" much more 

 closely connected with one another than is the case with the cells in 

 ordinär}' plain muscle. But how are they connected? No one knows. 

 Can cell-borders be demonstrated in the membrane of Bruch? Up to the 

 present no one has been able to point to them. Grynfeltt has emploved 

 nitrate of silver to demonstrate the cell-borders, but only in the posterior 

 part, and no one doubts that there are ceil-borders in that part of the dila- 

 tator; but in the anterior part, in the membrane of Bruch, they have never 

 been shown, as far as I know. Grynfeltt says nothing of the result of the 

 silver impregnation seen from the front, and no one has stated that by the 

 fuchsin method, or with iron-hæmatox3-lin staining, cell borders are seen in 

 surface-sections of the Bruch's membrane. If we look at the figures that 

 Retzius, Heerfordt and Forsmark give of a surface view of the dilatator, 

 we seek in vain for cell-borders. Both Retzius and Heerfordt, however, 

 describe a grouping of the fibrils in bundles, and Heerfordt has inter- 

 preted them as an indication of a division into muscle-fibres; but Fors- 

 mark is not convinced of the correctness of this, as he has only found 

 them in small areas. Fors.mark, who has largely employed iron-hæma- 

 toxylin in his work, states that there are no cell-borders to be seen in the 

 specimens from adult persons with this staining, but that it yields better 

 results in foetal material. 



