ADIPOSE TISSUE. 



35 



tions, together with elastic fibers (Fig. 25) which do not form 

 bundles and are not wavy. These fibers are bound together by 

 a cementing-material or ground-substance. The irregular crossing 

 of the fibers leaves spaces, called areolse, which give the name to 

 the tissue. In these are connective-tissue cells or corpuscles, of 

 which there are several varieties, the protoplasm of which pro- 

 duces the fibers and the ground-substance. These varieties are : 



FIG. 24. Cell-spaces in the ground-sub- 

 stance of areolar connective tissue (subcu- 

 taneous) of a young rat; stained in silver 

 nitrate (Huber). 



FIG. 25. Elastic fibers from the 

 ligamentum nuchae of the ox, teased 

 fresh ; X 500. At a the fiber is curved 

 in a characteristic manner (Bohm 

 and Davidoff). 



1. Lamellar cells; 2. Plasma-cells of Waldeyer; 3. Granule-cells. 

 Lymph-corpuscles are not infrequently seen, and in some places, 

 as in the choroid coat of the eye, the corpuscles contain coloring- 

 matter or pigment. 



Areolar tissue occurs under the skin as subcutaneous tissue, 

 beneath serous membranes as subserous, and beneath mucous mem- 



---. Nucleus. 

 L"" Protoplasm. 



Fat-drop. 

 Cell-membrane. 



FIG. 26. Scheme of a fat-cell (Bohm and Davidoff). 



branes as submucous, connecting these membranes loosely to the 

 structures upon which they lie. Enclosing muscle, blood-vessels, 

 and nerves, it forms their sheaths. It is also found in glands con- 

 necting the various parts with one another. 



Adipose Tissue (Fig. 27). When the areolae of areolar 

 tissue contain fat-cells, the tissue is called adipose. These fat- 

 cells or adipose vesicles consist of an envelope or sac, protoplasmic 



