438 B- WACE CARLIER 



Appearances présentée by the liver cells 12 hours after jeeding. 



Ail the cells contain abundance of glycogen, their nuclei hâve practi- 

 cally ail become clear with deeply staining newly formed chromatin. The 

 capillaries are narrow. 



From the foregoing one may conclude that the nuclei of the liver cells 

 exhibit two distinct periods of activity during the course of the digestion of 

 an ordinary meal. The first period begins soon after the meal is ingested 

 and long before any of the food has entered the duodénum; the nuclei 

 part with much of their chromatin to form a prezymogen and thereby 

 become exhausted; repair, however, soon sets in and they come to rest 

 between the 3 rd and 4 th hour. They do not long remain at rest, but are 

 prompted between the 4' 11 and 5 th hours to manufacture more prezymogen. 

 This second period of activity lasts longer than the first, the secretory 

 process is more intense, and complète recovery is delayed until the end 

 of the i2 th hour. No doubt the prezymogen so formed is converted into 

 zymogen within the cytoplasm, but it never appears in the form of granules 

 so familiar in gastric and pancreatic cells; it must, therefore, leave the 

 cells in a diffuse form and pass into the bile to be stored in the gall bladder 

 until required. 



Second séries of experiments with a purely proteid diet. 



After weighing and ségrégation the rats employed in this séries were 

 fed for a few days on a purely proteid diet to accustom their digestive 

 System to this kind of food. They were then made to fast for 24 hours, 

 given a full meal (by weight) of lean raw beef, killed as before at intervais 

 of one hour and treated as detailed under séries No. 1. 



Appearances presented by the liver cells 1 hour after feeding. 



The cell outlines are indistinct, the perl-grey stained cytoplasm is 

 ground-glass-like in appearance and exhibits numerous small vacuoles with 

 sharp mai-gins. Structureless material appears to be absent from the small 

 cells round the portai tracts and from those at the lobular margins general- 

 ly ; it is présent in very small amount elsewhere. Many nuclei are somewhat 

 swollen and contain little chromatin; that présent being reduced to small 



