XII.] 



ADIPOSE TISSUE. 



169 



fat-cells derived from this tissue form lobules, and are supplied 

 with blood-vessels very much as a gland is 

 supplied with blood; so that each lobule is 

 provided with an artery, vein, and capillaries. 



1. Fat-Cells. Cut out a small piece of the 

 omentum of a cat, selecting a piece that con- 

 tains a little fat, and mount it in normal saline. 



(ti.) (L) Observe the large, highly refractive 

 fat-cells arranged singly or in groups (fig. 137). 



(b.) (H) The large fat-cells of variable size FIG. 137. Fat-CeiK some 

 some of them polygonal highly refractive 

 contents, but no nucleus visible; connective- 

 tissue passing between some of the cells. 



showing a Nucleus. 

 The central one shows 

 crystals of margarine, 



X ioo. 



Place 



mil part of the omen- 



2. Action of Osmic Acid (H) 



tum of a cat or embryo 

 ox in ] per cent, osmic 

 acid for an hour. Wash 

 it thoroughly, and mount 

 in Farrant's solution. 



(fi.) (L) Observe the 

 fat-cells, which first be- 

 come brown and ulti- 

 mately quite black. The 

 fat-cells are in groups, 

 and their relations to the 

 blood-vessels can also be 

 seen in fig. 138. 



3. Membrane and 

 Nucleus of Fat-Cells 

 (H). Place a piece of 

 the omentum or subcu- 

 taneous adipose tissue 

 in absolute alcohol for 

 several days, and after- 

 wards in ether for a day 

 or two ; or the tissue 

 may be boiled for a few 

 minutes first in alcohol 

 and then in ether. 

 Transfer a small piece 

 to hsematoxylin and 

 allow it to stain for 

 several hours. Wash it 

 in water and place it in 



absolute alcohol. Extract it with turpentine, clear it up with clove- 

 oil, and mount it in balsam. 

 16 



B 



FIG. 138. Fat-Cells stained with Osmic Acid from lh: 

 Omentum of an Embryo Ox. A. The fat-cells in 

 groups or lobules, blackened by the osmic acid, and 

 showing their relation to the blood-vessels; 11. a-c 

 fat-cells in different stages of development. 



