CHAP. III.] ADIPOSE TISSUE. 17 



one kind of fibre to the other, that gives them their different 

 characteristics : the interlacing of the wavy bundles of finest 

 fibres, giving us the delicate web-like areolar tissue ; the close 

 packing of these bundles, giving us the dense opaque fibrous 

 membranes and bands; and the preponderance of the elastic 

 fibres, furnishing the extensile elastic tissue. 



This connective tissue proper, as we have already noted, is 

 used for purely mechanical purposes : forming inextensile bands 

 or pulleys ; strong protective membranes ; web-like, binding, and 

 supporting material; sheaths of varying degrees of density; 

 elastic bands or membranes; and it also serves to carry the 

 blood-vessels, lymphatics, and nerves to the parts which it 

 connects and covers. 



Adipose tissue. When fat first begins to be formed in the 

 embryo, it is deposited in tiny droplets in some of the cells 



f-3- 



c.l. 



FIG. 12. A FEW FAT-CELLS FROM THE MARGIN OF A FAT-LOBULE. Very 

 highly magnified, f. g. fat-globules distending a fat-cell ; n, nucleus; m, membran- 

 ous envelope of the fat-cell; c, capillary vessel; v, veiulet; c. t. connective-tissue 

 cell ; the fibres of the connective tissue are not shown. 



of the areolar connective tissue ; these droplets increase in size, 

 and eventually run together so as to form one large drop 

 in each cell. By further deposition of fat the cell becomes 

 swollen out to a size far beyond that which it possessed orig 

 inally until the protoplasm remains as a delicate envelope sur- 



