Histogonesis of tlio Adipose Tissue. 



419 



has a characteristic reticular structure not unlike the framework of 

 a lymph gland (Text Figs. 1 and 3). By means of special stains 

 and strong magnification its true structure may be seen. It was 

 mentioned by Hammar that connective fibrilla; were present in the 

 renal preadipose tissue (primitive organ). For this reason he 

 regarded it as a fibrillar connective tissue before the formation of 

 fat cells began. Hammar seems not to have had very convincing dem- 



Text Figure 3. Transverse section tlirongli the renal preadipose tissue 

 of a 25 em. foetus, hv, small blood vessel; fc, fibrillar connective tissue; /.-, 

 kidney ; L, lobule of preadipose tissue. Fixation, Zenker's fluid. Iron-hsem. 

 stain. X 50. 



onstrations of the presence of the fibrillae. This phase of the question 

 has not received the attention which it deserves. Fig. 6 (Plate II), 

 and Fig. 8 (Plate I) were drawn from the renal preadipose of an 

 18.5 cm. foetus. The section, from which Fig, 6 was drawn, was 

 stained by Mallory's anilin blue method — the blue having been al- 

 lowed to act about one hour. The connective tissue fibrillse (/') 

 stain with difficulty and then stain much less intensely blue than 



