ADIPOSE CONNECTIVE TISSUE. 93 



FAT CELLS IN CONNECTIVE TISSUE. In various parts of the 

 . animal body the connective tissue contains great numbers of 

 cells, which, enlarging equally in all their dimensions, attain a 

 considerable size, and have in their interior a large fat drop, com- 

 pletely filling them. The diameter of these cells reaches, in man, 

 0'2 millimeters. Their form is round or somewhat oval. Where 

 such fat cells are deposited in great number in the connective 

 tissue, they are divided into separate groups, or lobules, by strong 

 trabeculse. Each of these lobules possesses its own system of 

 vessels, which, with their branches, reach into the interior from 

 the surface, and are accompanied with fine bundles of con- 

 nective tissue ; here they divide into such numerous capillaries, 

 that the smaller groups of cells or even the individual fat cells, 

 are surrounded by vascular loops. 



Certain regions of the body in man are especially character- 

 ised by the presence of such adipose tissue. Thus it occurs in 

 the subcutaneous connective tissue, or panniculus adiposus, 

 which is very abundant in various parts of the body, as in the 

 mammary gland of the female, the pubic region, buttocks, and 

 sole of the foot ; in other parts it is less developed, but is only 

 absent in some few places, as the eyelids and male sexual 

 organs. Adipose tissue, moreover, is found in the omentum, 

 mesentery, beneath the pericardium of the heart, and on the 

 great vessels, around the kidneys, in the orbit, and in the fat 

 humps and adipose masses formed in the bodies of certain 

 animals, etc. 



In the fattening of animals, or in commencing obesity in 

 man, the adipose tissue increases at these points, and occurs in 

 large quantities also in regions of the body that with less 

 abundant supplies of food remain free from fat ; as, for example 

 in the connective tissue between the muscles. 



In large and fully developed fat cells, a thin smooth mem- 

 brane can be distinguished surrounding the oil drop, which, 

 however, collapses and becomes folded, if the cells are burst 

 by pressure, and the contained drop of oil be allowed to escape- 

 The membrane of the fat cells can also be brought into view in 

 a crumpled state by boiling the tissue with strong alcohol and 

 ether. 



The oil drop contained in these cells presents a faint yellow 



K 2 



