304 TUNICA VASCULOSA, BY PROF. A. IWANOFF. 



on either side by a longitudinal fasciculus of smooth muscular 

 fibres, the size of which varies considerably in different in- 

 stances.* Moreover, the thickness of the muscular fasciculus 

 is not alike on the two sides of the vessel. The smooth 

 muscles only accompany the short ciliary arteries as far as to 

 the posterior portion of the choroid ; the farther they are 

 traced forward in the direction of the ora serrata, the fewer 

 are the muscles. 



Detached muscles in the form of thin fasciculi are found 

 also distributed in the stroma of the choroid. 



3. The principal mass of the smooth muscular fibres of the 

 choroid is imbedded in the most anterior part of this membrane, 

 and constitutes the ciliary muscle (tensor choroideae, Brucke). 



The ciliary muscle (fig. 362) resembles a prism, bent into 

 the form of a circle, with its sharp border turned backwards. 



Fig. 362. 



Fig. 362. Section of the ciliary region of the eye of Man. a, 

 Meridianal muscular fasciculus of the musculus ciliaris ; b, deeper- 

 seated radiating fasciculi ; c c c, annular plexus ; d, annular muscle of 

 Miiller ; /, muscular lamina on the posterior surface of the iris ; g, 

 muscular plexus at the ciliary border of the iris ; e, annular tendon 

 of the musculus ciliaris ; h, ligamentum pectinatum. 



Its position is in the anterior and external part of the ciliary 

 body. The ciliary muscle is separated from the sclerotic by a 

 thin layer, the lamina fusca; and from the pigment which 

 covers the surface of the ciliary processes, by connective tissue. 



* H. Miiller, Verhandlung. der physikalisch-medicinischen Gesellschaft in 

 Wurzburg, Band x., Abtheil. ii., iii., p. 179. 



