THE CONNECTIVE TISSUES. 



79 



the cytoplasm, is enclosed in a delicate cell-membrane. The fatty 

 cells may occur singly in the midst of an apparently normal areolar 

 tissue of the usual type, but they are more frequently grouped to 

 form " lobules," held in position within the tissue by bands and 

 layers of unaltered areolar tissue. 



In sections of adipose tissue prepared after hardening the tissue 

 in alcohol the fatty globules can no longer be seen, since the alco- 

 hol dissolves the fat from the tissues. The partially collapsed 



FIG. 65. 



Section from the tongue of a rabbit : a, a, a, groups of fat-cells forming small masses of adipose 

 tissue in the connective tissue ; 6, b', connective tissue, 6 in longitudinal, and 6' in 

 cross-section ; c, small vein containing a few red blood-corpuscles. Near the centre of 

 the figure is another bloodvessel filled with corpuscles. The remainder of the figure 

 represents striated muscle-fibres in nearly longitudinal section. In the upper left hand 

 corner these show a tendency to split into longitudinal fibres (sarcostyles). 



membranes of the cells, with the cytoplasm and contained nucleus 

 forming an apparent thickening at one side, are all that remain to 

 distinguish the tissue (Fig. 65, a). 



Adipose tissue is widely distributed in the body. It serves as a 

 store of fatty materials which can be drawn upon as a reserve 

 stock of food when the nutrient supply of the body falls below its 

 needs. 



The usefulness of the fibrous tissues can be readily inferred 

 from their structure. The more open varieties of areolar tissue 

 serve to give support to the structures they unite and to the blood- 

 vessels, lymphatics, and nerves supplied to them. They also afford 

 spaces and channels for the return of the lymph, which transudes 

 through the walls of the capillary bloodvessels, carries nourishment 



