22 



(d) Areolar Connective Tissue. 



A small portion taken from the subcutaneous tissue of a young 

 cat is placed on a dry slide, the edges are drawn out and made to 

 adhere to the slide by allowing them to dry, while the center is kept 

 moist by breathing upon it. In this way a thin film is obtained. 

 Place a drop of normal salt on a cover glass and invert it over the 

 center of the film. 



Examine under high power, using one of the smaller 

 openings of the diaphragm. Observe the bundles of white 

 fibrous tissue, composed of elementary fibrils, crossing the 

 field in every direction, and forming a felted network. On 

 and between these bundles, yellow elastic fibres will be seen. 

 They have a more definite outline, and branch and anasto- 

 mose. Search for connective tissue cells. 



Carefully elevate the cover glass, and add a drop of 1% solu- 

 tion of acetic acid. 



In a few moments the bundles of white fibrous tissue 

 will swell and appear homogeneous, while the unaffected 

 yellow elastic fibres will stand out boldly ; the nuclei of the 

 fixed connective tissue cells can now be more clearly seen. 

 Sketch a bundle of white fibrous connective tissue, some 

 yellow elastic fibres, and a number of the connective tissue 

 cells. 



(e) Cell Spaces in Areolar Connective Tissue. 



A small piece of areolar connective tissue was removed from a 

 young animal, spread out on a dry, clean slide, immersed for 15 

 minutes in a 1% solution of silver nitrate, rinsed in water, placed in 

 95% alcohol, and exposed to direct sunlight. The sunlight reduces 

 the silver nitrate giving the tissue a brown color. It was then 

 removed from the slide, hardened in alcohol, and cleared in oil of 

 bergamot. Mount in balsam. 



Study under high power. The ground substance of 

 the tissue is stained brown, and the irregular, branched, 

 and often anastomosing cell spaces are left unstained, and 

 thus are clearly seen. Sketch. 



(f ) Tendon. 



Tendons taken from the tail of a rat were suspended in alum 

 carmine for 24 hours. Tease in gum glycerine. 



