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



answer to the immediately underlying veins, and that the bundles make 

 use of these vessels as their attachments. 



Grunert expresses himself very cautiously (p. 337) on the subject of 

 the "arcades" of dilatator-bundles which he has described in the periphery 

 of the iris, saying that "diesen cirkulären Fasern muf? wohl eine besondere 

 Bedeutung zugeschrieben werden, doch wage ich bestimmtes nicht zu be- 

 haupten". Von Szily states that the dilatator gradually becomes smaller 

 as it approaches the periphery, and that the muscle-cells gradually pass into 

 the front laver of the epithelium. This transformation is not complete until 

 the beginning of the first ciliary process. "Bis dahin erkennt man unter 

 den an Höhe mehr und mehr zunehmenden Epithelzellen noch immer eine 

 allmählich dünner werdende Faserlage als Fortsetzung der Bruchschen 

 Membran". From this membrane he has then seen single groups of smooth- 

 muscle cells radiating freely into the connective tissue. "Diese terminalen 

 Ausstrahlungen beginnen schon in peripheren Gebiet der Iris, die letzten 

 sich ablösenden Bündelchen gehören den Bereich des Corpus ciliare an. 

 So hat es den Anschein, als würde sich die Bruch'sche Membran unter 

 allmählicher Verdünnung gewissermafaen auftassern". \'ox Szily has also 

 found these irradiations unevenly distributed. Most of them are found in 

 the ciliar}' depressions. "Diese Ausstrahlungen stellen in ihre Gesammtheit 

 die ciliare Insertion des Musculus dilatator pupillae dar". 



While quoting former investigators who have carefully studied the 

 peripheral thickenings and off-shoots, and regarded them as the ciliary 

 insertion of the dilatator muscle, Forsmark (p. 58) points out how remarkably 

 different they are frequently found to be, how differently they aie 

 developed as regards strength, and how comparatively weak their contractile 

 substance is, and thinks that from this the conclusion may be drawn that 

 these formations are of a chance character, and that it is doubtful whether 

 they are of much importance to the insertion of the muscle. "Die haupt- 

 sächliche Insertion der Dilatatorschicht am Ciliarrande wird ohne Zweifel 

 dargestellt durch Bindegewebsfibrillen, die in der Irisbasis und dem Ciliar- 

 körper in der Richtung nach innen und hinten gegen die Muskelschicht 

 ziehen, um sich an der \'orderfläche derselben zu befestigen". As both 

 the "epithelial processes" and the "hooks", and also the growing-in of the 

 epithelium into the stroma, as I have shown them in the letterpress-figure i, 

 all go out towards the ciliary body, and as they undoubtedly originated 

 in proliferation of the epithelium, some of which has been transformed into 

 muscle-cells and some has not, it must be reasonable to consider them as 

 different types of attachment for the periphery of the dilatator muscle. In 

 this we are supported, in my opinion, by the investigations, few though 

 they are, of the embryology of the dilatator. \'on Szily has found in the 

 late foetus and the newborn child, a fillet-like proliferation of the foremost 

 layer of epithelium answering to the ciliary depressions, and expressed as 

 his opinion that they represented the rudiments of the peripheral off-shoots 



