Histogenesis of the Adipose Tissue. 427 



are present separated by thin layers of protoplasm. The cell mem- 

 brane (m) is now clearly shown. The cell is still pointed at the 

 ends. 



Text Fig. 6 shows two cells from the subcutaneous tissue of the 

 brisket of a 24 cm. frotus. They lie near a blood vessel around which 

 a few fat cells have appeared. The processes of the preadipose cells 

 of this region are somewhat thinner than those of the renal tissue. 

 Both cells, especially cell A, show fat droplets in their ])rocesses. 

 I have not determined the exact way the cell process disappears, but 

 several cells like cell A have been observed. It seems that in these 





777 



g .-L. .m 



A 



Text Figure 7. Three cells from the edge of a renal fat lohule of a 42 cm. 

 foetus. A, before formation of cell membrane. B, shows first appearance of 

 cell membrane. C, later stage, f, spaces oc-eupied by fat droplets ; g, Altmann 

 granules; m, cell membrane; n, nucleus. Fixation, Zenker's fluid. Stained 

 with iron-hsem. and eosin. X 1200. 



cells the cell process is transformed into fat droplets which are moved 

 up into the body of the cell. 



Text Fig. 8 represents two cells well into the edge of a fat lobule. 

 They were drawn from the same section as those shown in Text 

 Fig. 7. The cells have increased gTcatly in size, though the processes 

 have not yet disappeared. The protoplasm is thickly studded with 

 Altmann granules. The cell membrane is sharply marked except on 

 the processes. 



Text Fig. 9 was drawn from the same specimen from which 

 Text Figs. 7 and 8 were taken. The cells lie well into the edge 



