CONCERNING THE SECRETION OF FERMENTS BY THE L1VER CELLS 44 l 



spherules. The cell outlines are much more distinct and the cells swollcn 

 especially in the middle and inner zones where there are also many large 

 vacuoles, the cytoplasm is composed of moderately coarse spherules. 



Many nuclei are swollcn and clouded, they contain few nucleoli of 

 which only one hère and there is migrating; the structureless material is 

 rather more abundant than in the previous spécimens though still diffuse 

 with slight tendency to run into clurnps. The capillaries are slightly 

 dilated. 



Appearances presented by the liver cells 8 hours after feeding, fig. 6. 



The cells are well filled with cytoplasm precipitated in very large 

 spherules and containing a few small vacuoles of about the same diameter 

 as the spherules, especially in the small cells bordering the portai tracts 

 which stain of a pinkish grey tint. Ail the nuclei are swollen, rounded and 

 cloudy, some more than others, the nucleoli are as a rule small, a few large 

 ones in process of migration being, however, présent. 



The structureless material is again abundant and arranged in large 

 masses. The capillaries are not dilated, or only slightly so. At this hour, 

 therefore, ail the cells are in process of repair after zymogen formation. The 

 large size of the cytoplasmic spherules during this and the previous hour 

 is worthy of note, because, though they are artificial products of fixation, 

 their size may be taken as an index of the amount of coagulable material 

 taken up from the blood to assist in both cellular and nuclear repair. 



In this séries of préparations we are again confronted with the fact 

 that the liver cells hâve twice been called upon to produce prezymogen. 

 The first sécrétion is already well on the way by the end of the first hour, 

 recovery from which is fairly advanced by the end of the second hour and 

 completed an hour later; the second, beginning between the 4 th and 5 th 

 hours is more intense and of longer duration and hardly completely 

 recovered from by the end of the <s th hour. When compared with the 

 second, the first effort is feeble and of short duration. 



Another feature in the process well brought out by this séries of ex- 

 periments is the method of working in relays, the outer zone is the first to 

 secrète and the first to recover, closely followed by the middle zone which 

 is succeeded in turn by the innermost zone of the lobules. 



Thèse changes must also be accompanied by changes in blood pressure 

 within the liver as the capillaries are widest when repair is beginning, that 



