CONNECTIVE TISSUE. 67 



sire able to recognize the smallest droplets of fat. The large 

 globule which is formed by the coalescence of the smaller drop- 

 lets increases in size until it fills nearly the whole cell. The 

 nucleus with the small quantity of protoplasm that remains is 

 pushed to the periphery of the cell, which is now known as a 

 signet-ring cell (Figs. 33, 35). The cell membrane thickens 

 and holds the fat within it, thus preventing the fat globules 

 from running together. The cell membrane can easily be seen 

 in fat treated with alcohol, ether, chloroform, or ethereal oils. 

 By the accummulation of fat the cells may become as large as 

 130 [L in diameter. Fresh fat is usually yellow or orange in 

 color, but is of different tints in different animals. 



After death groups of needle-like crystals form in the cells. 

 These consist of palmitic and stearic acids, the so-called mar- 

 gar in crystals (Fig. 35). 



r 



t^MP Connective tissue 



f L R~ fibrils 



Fat crystal*- ^ > xi 



Fat cell, 

 'surface view 



Blood capillary-^- 



Fat cell, 



*^ j lateral view 



ST7 i. _ _ 



Fat from the subcutaneous layer of the skin of a white mouse. X 200. 



Fat is arranged characteristically in round lobules separated 

 from one another by fibrillar connective tissue, which forms a 

 capsule for each lobule. In the lobule, however, between the 

 cells we find only very few fibril bundles. Thus fat is merely 

 a modified fibrillar connective tissue, in which the cells are 

 changed specifically, and the fibrils subserve a subordinate func- 



