362 SPECIAL HISTOLOGY. 



tissues. In the outer portions of the tunic, this stroma is 

 formed of fusiform or stellate, very irregular, and extremely 

 pale, or more or less brown nucleated cells, 0*008 — 0"02 /r/ long, 

 which anastomose frequently with each other by shorter or 

 longer, usually very delicate (0-0005'"), but rather rigid pro- 

 cesses, and from their great number represent a lax membra- 

 nous tissue. There would be nothing very peculiar in this, 

 and these cellular networks might properly be classed with 

 other similar anastomosing pigment-cells, as 

 for instance in the batrachian larva (most 

 characteristic in Alytes) ; but in the inner 

 layers of the choroid, and especially in the 

 membrana chorio capillar is, they gradually 

 pass into homogeneous, nucleated tissue, at 

 first containing a little pigment, but after- 

 wards none at all; and which, although in 

 appearance very similar to homogeneous 

 connective tissue, is distinguished from it 

 by its resistance to acids and alkalies, and 

 approximates the elastic tissue, from which, however, it likewise 

 differs in its trifling elasticity and paleness ; whence it is better, 

 at present, to regard it as sui generis. 



The ciliary ligament of anatomists, or the musculus ciliaris 

 s. tensor chorioidea (fig. 296 k), the really muscular nature of 

 which was recognised almost simultaneously by Briicke and 

 Bowman, is a tolerably thick layer of radiating smooth mus- 

 cular bundles, passing from the most anterior border of the 

 sclerotic upon the ciliary body, and ceasing in its anterior half, 

 opposite the part where the ciliary processes are placed, inter- 

 nally. More precisely described, the ciliary muscle arises 

 where the sclerotic is grooved for the formation of the venous 

 sinus of Schlemm, and, in fact, from a special, dense, smooth 

 tract (fig. 296 I), which, forming the inner wall of the canal in 

 question, coalesces with the sclerotic, and also receives a por- 

 tion of the fibrous network, into which the membrana De- 

 moursii is prolonged, the fibres of which are completely blended 

 with the elements of the tract in question, and resemble 

 the others in all respects except that they are much finer, 



Fig. 299. Cells from the stroma of the choroid: a, pigment-cells; b, uncoloured 

 fusiform cells; c, anastomoses of the former. Human ; x 350 diam. 



