30 NORMAL HISTOLOGY. 



nucleus. In thin sections of adipose tissue, by no means every fat-cell 

 exhibits a nucleus, since, owing to the small size of the latter in comparison 

 with the diameter of the cell, many sections include zones lying beyond the 





5 



J^-.^A. i ~\cjf ~ ~r ^Y7**^3B9V' - 't*' *^~ ^"^T '. 



^V-%^ L '-">V'<. 

 ; ^ x ~s . 



jr***' ^^^"^ 



'V 



' r ->' 



"si* 



FIG. 43. Portion of omentum, showing groups of fat-cells between the bundles of connective tissue. X 150. 



nucleus. During life the fat within the body is fluid. Quite often radiating 

 clusters of slender fat-crystals are observed within the adipose cells. These 

 are margarin crystals that formed when the fat solidified after death. 



Fat-cells occur usually in groups supported and held together by highly 

 vascular connective tissue. In localities possessing considerable masses of 

 fat, as beneath the scalp and the skin, the cells are grouped into lobules 

 which appear as yellow granules to the unaided eye; in such positions the 



individual fat-cells lose their 

 spherical shape and assume a 

 polyhedral form as the result 

 of the mutual pressure of the 

 closely packed vesicles. 



In connective tissue ele- 

 ments about to become fat-cells, 

 minute isolated oil-drops first 

 appear t within the cytoplasm 

 in the vicinity of the nucleus. 

 These droplets increase in size 

 and number, coalesce and grad- 

 ually encroach upon the cyto- 

 plasm until the latter is reduced 

 FIG. 44. Young fat-ceils from subcutaneous tissue, x 500. to a thin, almost inappreciable 



envelope, which completely in- 

 vests the now huge distending oil-drops. The nucleus, likewise, is displaced 

 towards the periphery, where it appears in profile as an inconspicuous cres- 

 cent embedded within the cytoplasm (Fig. 44). When the invasion of the 



Peripheral 



zone of 



cytoplasm - 



enclosing 



oil-drop 



Young fat- 

 cell 



Connective 

 tissue cells 



1 



