LIVER CELLS FROM CHICK EMBRYO 299 



The liver cells migrated out in the form of a membrane or 

 sheet. No cell division was observed in them. 



The liver cells showed ectoplasm and endoplasm, and in the 

 latter were seen mitochondria, bile granules, neutral red granules 

 and fat globules. The ectoplasm sometimes contained a few 

 neutral red granules. 



The mitochondria were very numerous and in the form of more 

 or less irregular granules, varying in size even in the same cell. 



Bile granules (bright green masses) were only occasionally 

 seen in the liver cells. These showed a great affinity for neutral 

 red and changed to orange, brown, reddish-brown and finally to 

 a very dark red color when this dye was added to the culture 

 medium. 



The cytoplasmic or 'degeneration' granules varied in number; 

 only a few were seen in the cells of young cultures. They gradu- 

 ally increased in number and size in the older cultures. A few 

 were seen in the ectoplasm where their movements were more 

 marked. They had a great affinity for neutral red and trypan 

 blue, taking up the former rapidly, the latter slowly, and losing 

 the neutral red rapidly and trypan blue slowly as the cells died. 

 The granules took up the two dyes at the same time, the color 

 varying between red and blue according to the relative strength 

 of the dyes. 



Neutral red and trypan blue seem to be taken up only by 

 pre-existing granules and by the same granules. 



Fat globules increased in number with age of the chick, but 

 not with the age of the culture. They were seen in the liver 

 cells and also free in the media. 



Degeneration occurred either by vacuolization or by bleb 

 formation. 



The endothelial cells formed the usual loose, reticular-like 

 outgrowths. Since the embryonic liver contains little or no 

 mesenchyme, it is very probable that many of the so-called 

 mesenchyme cells were from the endothelium of the sinusoids. 



Wandering cells occurred frequently and often contained bile 

 granules. 



Debris ( or fibrin?) from the explant often occurred in large 

 amounts, at times obscuring the outgrowths. 



