FORMATION OF CELL WALL OF ADIPOSE TISSUE. 135 



In insects the "fat cells " are often of enormous size, 

 consisting of aggregations of very small oil globules, 

 which collect around the mass of bioplasm that has 

 taken part in their production. In the livers of many 

 fishes, particularly the eel, a somewhat similar ar- 

 rangement may be observed. In these cases the 

 nutrient matter passes in the interstices between the 

 already formed oil globules to the bioplasm in the 

 centre. The circumferential portions of the latter 

 die, and undergo transformation into fatty matter 

 which is deposited within that already produced. 

 The globules on the outside of the cell or those on its 

 surface are therefore the oldest. 



191. Formation of the cell wall of the adipose 

 Tesicle. At the same time that the oil globule depo- 

 sited in the bioplasm of the developing adipose tissue 

 increases, a change of another kind is taking place 

 upon the surface of the mass. The living matter in 

 this situation dies and becomes changed, so as to 

 form a delicate transparent structureless membrane, 

 which increases in extent as its contents become aug- 

 mented by the absorption of nutrient material into 

 the included bioplasm. The so-called wall of the 

 adipose vesicle is therefore formed in accordance with 

 the mode of production of formed material generally. 

 But the wall of the adipose vesicle is of excessive 

 tenuity, and readily permeable to fluid in both direc- 

 tions, so as to allow for the very free passage of nu- 

 trient material to the blop^sm in the interior, and 

 that of fluid resulting from the changes of the fro- 

 pi tsrn in the opposite direction towards the blood. In 

 this way the rapid increase and removal of adipose 

 material is rendered possible. 



12. Is adipose tissue only altered connective 

 tissue ? Some observers, consider that the adipose 

 tissue is not a distinct texture at all, but hold that 

 the fat cell is invariably developed from the corpuscles 

 of connective tissue a view which is certainly 



