25 



of an occasional connective tissue cell. What is the staining reac- 

 tion with picrofuchsin ? Compare with 26. 



29. Ligamentum nuchae. Horse. Teased preparation. 

 With your needles tease out very carefully a small piece of liga- 

 mentum nuchae obtained from the instructor. Remember that the 

 course of the elastic fibers is longitudinal, and therefore tease by 

 pulling the fibers to the side, trying to keep them parallel. Tease 

 carefully and thoroughly. Mount in glycerin jelly. 



Note the anastomosing and branching of the fibers ; are trans- 

 verse markings to be detected ? 



PIGMENT CELLS. 



30. Pigmented pia. Sheep. • From the frontal region of the 

 brain. Now in 95% alcohol ; no staining required. -Clear and 

 mount in balsam. 



Note the shape and anastomosing of the pigment cells, the pig- 

 ment granules, and the clear space occupied by the nucleus of the 

 cell. 



31. Pigmented peritoneum. Nedurus. Picric alcohol ; 

 peritoneum removed and now in 82% alcohol. Stain with hema- 

 toxylin 10 minutes, eosin 15 seconds (§ 94). Mount in balsam. 

 Since this preparation is not fixed to the slide, care must be taken 

 in changing fluids (§ 65, a). 



Note the shape, the nucleus, the pigment granules, and the 

 state of expansion or contraction of the pigmented connective tissue 

 cells. Does the preparation show cells well expanded and cells 

 quite contracted ? 



