1923. No. 23. A CASE OF CONGENITAL MIOSIS. I y 



darauf gegen den Ciliarrand hin allmählich wieder schwächer". Inside, says 

 Forsmark, they consist entirely of radial muscle-cells; hut after thev have 

 come out among the ciliary processes, first the hindmost cell-layers, and 

 then the front ones, bend in a more or less circular direction. In this way 

 they sooner or later escape from the the rest of the muscular layer, and 

 become surrounded on all sides by the iridian stroma. "Unter beständiger 

 Abnahme an Mächtigkeit durch den Abgang zirkulärer Zellen von der 

 Rückseite erreichen sie die Irisgrenze und endigen hier unter Umbiegung 

 nach der einen oder anderen Seite". F'orsmark has only in exceptional 

 cases found bundles of radial muscle that have gone beyond the border of 

 the iris and thus entered a little way into the corpus ciliare. On the other 

 hand it was usual for circular cell-bundles to turn to the nearest ciliary 

 process; and they could frequently- be traced to a considerable depth in 

 the basal part of the processes. 



It will be seen that the descriptions of the periphery of the dilatator 

 muscle dift'er considerably. I have gone through our Anatomical Institute's 

 collection of microscopic sections (single sections) through the iris, and have 

 found that most of them show the dilatator as Grynfeltt and Herfordt 

 state it to be. In some few sections, however, I have seen a short bundle 

 passing outwards and often forwards in the stroma at the base of the iris ; 

 but to be able to judge of the exact conditions one should certainly have 

 series at one's disposal. This is apparent from Forsmark's description 

 where there is a diflference between the dilatator in the depressions between 

 the ciliary processes and under the process itself. A real illustration of 

 them can consequent!}- only by given b}- a sufficiently long series which 

 includes both regions. Fig. 12 is from such a series. 



To be able to form a perfect!}' true judgment in this matter, however, 

 the series should be not only sections cut in a radial direction, but also in 

 "tangential" (transversal) and "frontal" planes. The club-shaped end of the 

 dilatator muscle in fig. 12 could be traced through 12 sections of io/< 

 without greatly changing either appearance or direction'. As I have 

 found no illustration of the periphery of the dilatator quite answering to 

 this figure in any of the works of the authors that I have studied, I have, 

 for purposes of control, cut some series through the peripheral part of 

 some irides, to see whether similar cases were often to be found ; for the 

 illustration that most resembles my fig. 12 is Grl-nert's fig. 9, and it will 

 at once be seen that after all there is a great dift'erence between his figure 

 and mine, as the thickening in his material lies a litde within the iris, and 

 diminishes before the periphery of the iris is reached, whereas in my 

 case the thickening only begins, so to speak, after the periphery of the 

 iris is reached. I think that Grunert's figure about answers to Forsmark's 

 description of the strengthening bands. 



• \-ide foot-note, page 14. 



Vid.-Selsk. Skrifter. I. M.-N. Kl. 1923. No. 23. 



