HISTOLOGICAL STUDIES 



43 



Compare these cells (columnar epithelium; see Fig. 15, d) 

 with those of Ex. XXII (squamous epithelium; see Fig. 14, 

 a, 2 and 3, and c). How do they differ? Note the pro- 

 tective character of these layers of cells with reference to 

 the underlying layers. (One feature of this protection is 

 prevention of the action of digestive fluids upon the under- 

 lying muscles and other forms of tissue.) 



XXVI. CONNECTIVE TISSUE (OPTIONAL). 



Apparatus. Prepared slides of intermuscular tissue, cartilage, 

 and bone, compound microscope. 



Directions. A. Intermuscular Tissue. Draw, under the 

 low power. Note two classes of bundles of fibers (white 

 fibers and elastic). The elastic fibers are single and are 

 more sharp in outline than the 

 white. Find one of the cells (or 

 corpuscles) and focus with the 

 high power. Draw it, and show 

 in your drawing its relation to 

 the two classes of fibers. From 

 your study, which part of this 

 tissue should you say was most 

 important, the cellular part or 

 the intercellular fibers? 



B. Cartilage (hyaline). Note 

 the solid character of the in- 

 tercellular matrix, the outlines 

 of the cells with their proto- 

 plasm and nucleus, the lacunce, or pits in which the cells 

 lie, and the capsules inclosing these lacunse. Which part of 



Corpuscle 



Bundle of White Fibers 

 FIG. 16. Intermuscular Tissue. 



