/ - 



'**" 



A THE CONNECTIVE TISSUES. 



Fat-cells embedded in subcutaneous areolar tissue : f, fat-cells ; n, nucleus; c, 

 connective-tissue corpuscles ; iv, migratory cells ; e, elastic fibres ; b, capillary 

 blood-vessel. 



characteristic appearance of the tissue. Whether the fat-cells are 

 developed from elements especially set apart for this role, or whether 

 they are but modified ordinary connective-tissue cells, is still a dis- 

 puted point ; there are, however, strong reasons for holding the latter 

 view as correct. 



Examined after the usual preparatory manipulations, and in places 

 where the cells maintain their individual forms, as in the omentum, 

 adipose tissue is seen to be made up of relatively large, clear, oval 

 or spherical sacs. The transparent contents are limited by a delicate 

 envelope, composed of cell-membrane and an extremely thin layer 

 of protoplasm ; on one side of the sac a local accumulation marks 

 the position of the nucleus. 



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

 areolar tissue, through which ramifies a rich, vascular net-work. In 

 localities possessing considerable masses of adipose tissue, as beneath 

 the scalp and the skin, the cells are grouped into lobules, and these 



protoplasm into the white^fibrillae, the greatly elongated cell-body 

 begomingtlTe nbres.~"While such cbnversioiTraoes probably occur A f 

 it Is certain that the indirect mode, whereby the fibres originate \ > 

 within an indifferent matrix, is the more usual; the production of \ 

 the matrix or ground-substance itself, however, must be attributed \ ! 

 to the cellular elements. Regarding the development of the \l 

 elastic fibres, strong evidence supports the view that the fibres are 

 produced without the direct action of the cells, but result from the 

 fusion of longitudinally-disposed rows of minute particles, which 

 appear within the indifferent intercellular matrix. 



Adipose tissue must be regarded as a member of the group of 

 connective substances, since the accumulation of oily matters within 

 the protoplasm of connective-tissue cells is responsible for the highly 



FIG. 48. 



