THE CONNECTIVE TISSUES. 



83 



4. Adipose Tissue (Fig. 67). — Fat or adipose tissue is a modifica- 

 tion of the more open or loosely-textured areolar tissue, caused by 

 the accumulation within the cytoplasm of the cuboidal cells of drops 

 of oil or fat. The cells which have become the seat of this fatty 

 infiltration are enlarged, and their cytoplasm, with the enclosed 

 nucleus, is pressed to one side, the great bulk of the cell being occu- 

 pied by a single large globule of fat. This globule, together with 

 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. 67. 



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

 tissue in the connective tissue ; b, b', fibrous tissue, b in longitudinal, and b' 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 (Figs. 67, a, and 68). 



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

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



