296 THE TISSUES. 



membrane, but very thick comparatively even T oVo of an inch.' 

 4th. The fat-cell is also larger than other cells, being from TT^S to 

 T | 7 of an inch (Kollike-r), and averaging g <y of an inch in diameter. 

 They are smallest in yonng animals. Those, however, of the same 

 mass differ in size. They present no peculiarity in respect to form ; 



Fig. 185. Fig. 186. 



Fig. 185. Normal fat-cells from the breast, a. Without reagents, b. After being treated with ether, 

 whereby the fat is exhausted and the folded delicate membrane remains. Magnified 350 diameters. 

 (RMker.) 



Fig. 186. Fat-cells assuming the polyhedral form from pressure against one another ; from the omen- 

 turn. (Magnified about 300 diameters.) 



being globular originally and in young animals, and polygonal 

 when pressed together in a mass in the adult. (Fig. 186.) 



In color, adipose cells are usually of a yellowish shade; but 

 lighter in young than adult animals. Hence adipose tissue is usu- 

 ally of this color. 



The contents of the fat-cells become solid at the temperature of 

 63 (Fahr.) and lower, since the oleine congeals at this temperature. 

 After death, therefore, human fat is solid. 



II. The connective tissue between the fat-cells usually presents 

 nothing peculiar, it 'being mere areolar tissue. It is, however, 

 sometimes merely a connective substance or plasma. (Kblliker^) It 

 has already been shown that fat-cells often fill, partially or entirely, 

 the areolas of areolar tissue, as of the superficial fascia ; though a 

 small amount of areolar fluid still exists between the cells, except 

 where they are in perfect contact. But in case of adipose tissue, 

 the cells are aggregated in larger masses, and the connective areolar 

 tissue is comparatively slight in amount. These masses take the 



1 Todd and Bowman think each fat-cell has its own envelop of areolar tissue, 

 and its distinct vessels. This is, however^ certainly not the case with all of them, 

 though it is with some. 



