Quain's elements of anatomy . the spacesof Fontana, and its fibres,spreading out, are directedbackwards (fig. 332, k),to be inserted into thechoroid oj^posite to theciliary processes, andpartly further back. Neartheir insertion the fibrespass equatorially and in-ter-cross so as to formpeculiar stellate to Waldeyer,a small portion (theoutermost) is sometimesinserted into the sclerotic coat (fig. 332, m). These antero-posterior, ormeridional and radictUng fihres, pass at the side next the iris into a ring offibres (l), which have a circular course around the insertion of the ir
Quain's elements of anatomy . the spacesof Fontana, and its fibres,spreading out, are directedbackwards (fig. 332, k),to be inserted into thechoroid oj^posite to theciliary processes, andpartly further back. Neartheir insertion the fibrespass equatorially and in-ter-cross so as to formpeculiar stellate to Waldeyer,a small portion (theoutermost) is sometimesinserted into the sclerotic coat (fig. 332, m). These antero-posterior, ormeridional and radictUng fihres, pass at the side next the iris into a ring offibres (l), which have a circular course around the insertion of the set forms the circular cilictry ninscle of H. Miiller. This circularmuscle is much developed in hypermetropic eyes, but is atrophied, ormay even, it is said, be absent in myopic (Iwanoff). The ciliary muscle,at least its inner part, was formerly described as the ciliary ligament. Inbirds the ciliary muscle is composed of cross-striped muscular fibres. The nerves of the choroid will be described with those of the THE IRIS. The iris is the contractile and coloured membrane which is seenbehind the transparent cornea, and gives the tint to the eye. In itscentre it is perforated by an aperture—the inqnl. At its circumferential border, which is nearly circular, the iris is THE lEIS. 405 continuons with the choroid, and by the ligamentum pectinatmn, withthe cornea : the fiee inner edge is the boundary of the j^upil. The irismeasm-es half an inch across, and, in a state of rest, about one-fifth ofan inch fi-om the cii-cumference to the pupil. The anterior surface,yariously coloured in different eyes, is marked by waved lines convergingtowards the pupil, near which they join in a series of irregular eleva-tions ; and, internal to these, other finer lines pass to the pupil. Theposterior surface is covered -ndtli dark pigment, and is marked by anumber of fine converging folds or thickenings prolonged fiom thecihary processes. Fig. 339. Fig. 340.
Size: 1284px × 1947px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., boo, bookcentury1800, booksubjectanatomy, booksubjecthumananatomy
