27 



Cut the sections very carefully and as thin as possible. Place 

 6-10 good sections in an alum solution (^4%) in a watch-glass for 

 5-10 minutes ; place 3-4 sections on a slide in a drop of normal salt 

 solution ; cover and examine, studying the character of the cells 

 arid their nuclei, their grouping, the character of the matrix. 



After the 5-10 minutes, drain off the alum solution from the sec- 

 tions in the watch-glass. Mount one-half of them directly in gly- 

 cerin jelly; the remainder, stain in hematoxylin for 5-10 minutes, 

 wash in water, and mount in glycerin jelly. These two prepara- 

 tions are to be studied in connection with the sections in normal salt 

 solution, for the structure of hyalin cartilage. 



(38). Hyalin cartilage. Mammal. For this, study 38, 

 noting the structure of the cartilage, the grouping of the cells, their 

 shape and arrangement, in the deeper portion and at the articular 

 surface, and the corresponding difference in the density of the matrix. 

 Compare with 33. 



34. Elastic cartilage. From the ear of the ox (or horse). 

 Picric alcohol fixation. Make free-hand sections, cutting them as 



thin as possible. Place three or four of the thinnest in water for ,5 



2.O . . . 1-o rxct>o\^S 



minutes, stain in hematoxylin *, minutes, picrofuchsm f-a minutes ; 



dehydrate, clear, and mount in balsam. Study carefully, noting the 

 areas of hyalin matrix surrounding the cells and the reticulum of 

 elastic tissue. Compare with sections of hyalin cartilage, 33, 38, 

 and contrast with the ligamentum nuchae (28). Note again the 

 different staining reaction of the elastic fibers of the cartilage and the 

 white fibrous tissue surrounding the cartilage. 



35. Fibro-cartilage. From the inter-vertebral disc. 

 Assigned for study. ; ; stained with 



There are shown the interlacing bundles of white fibrous tissue with 

 the cartilage cells surrounded by hyalin matrix scattered through 

 the tissue. Compare with the elastic cartilage, 34, and in this com- 

 parison recall the staining reaction of the white and the elastic fibers 

 (26, 28). 



BONE. 



36. Dry bone. Homo. Transection of femur. To be ground 

 down to a thin section and mounted in accordance with the special 

 directions, 133-134. 



