THE CILIARY MUSCLE. 261 



nerves which is found in the neighborhood of its 

 posterior attachment, will be exhibited with the 

 lamina suprachoroidea. 



Preparation 17. Ciliary muscle and lamina 

 suprachoroidea, To prepare these, the anterior 

 part of the eye is to be pinned down under spirit, 

 and the cornea and sclerotic cut away at one part, 

 when the radiating fibres of the ciliary muscle will 

 be seen passing meridionally from their origin 

 opposite the attachment of the iris, and forming a 

 layer which becomes gradually thinner as it extends 

 backwards and finally ceases in the superficial part 

 of the choroid. A small piece of the muscle is 

 seized with sharp forceps near its origin, and, by 

 carrying the instrument slowly backwards, is gradu- 

 ally torn away from the rest. It will be found that 

 the shred which comes away generally spreads out 

 posteriorly into a very thin membranous lamina, 

 this being in fact a piece of the lamina suprachoroi- 

 dea into which the superficial fibres of the ciliary 

 muscle are inserted. A considerable length may be 

 torn off in this way, and the piece so obtained is to 

 be floated directly on to a slide, Avhich is dipped for 

 the purpose into the spirit. It must be moved with 

 great care, so as to avoid folds or creases. The slide 

 is quickly wiped free of spirit, with the exception of 

 that which immediately moistens the specimen, and 

 a drop of freshly-filtered logwood placed upon the 

 tissue, and allowed to remain on it for ten minutes. 

 The staining solution is then poured off,, and the 

 remains of it are removed by allowing a drop or two 

 of water to flow gently over, without disturbing the 

 position of the membrane. Finally a cover-glass is 

 laid on, and a drop of glycerine allowed to run in at 

 the edge of the cover-glass. 



The preparation so obtained is, if successful, a 

 very striking one. Besides the branched pigment 

 cells of the choroidal tissue, and a certain number of 

 cells, similar to white blood corpuscles, 911 the sur- 

 face of the membrane, a number of large, round or 



