CIIAI-. iv.] METAKOL1C l'i;<>< i I I HJI BODY. 666 



the various forms of carbohydrate!, or with proteids, or with 

 other substances, is of the same kind and pn->,-nt> tin- same 

 characters; at least we have no evidence to the contrary. 



The storing-up of glycogen in tl: liver is also influenced 

 by other circumstances than the taking of food. For inst.iix 

 in the frog an increase of glycogen takes place during the win- 

 ter months. In the summer months the liver of a frog will \m 

 found to contain very little glycogen, Fig. !<>; r. unless the 

 animal has been unusually well fed; whereas a liver examined in 

 mid winter, Figs. 105, 106 A, will be found to contain a consider- 

 able quantity, even though no food has been taken for months. 

 In such a case the material for the formation of the glycogen 

 in the liver must have been furnished by some part of the body 

 of the frog, and could not, as may be the case when a meal 

 leads immediately to an increase of glycogen, be supplied 



B 



FIG. 106. THREE PHASES OF THE HEPATIC CELLS or TH FBOO. (Langley.) 



A. Cells rich in glycogen. Taken from a frog during winter. The cell* 

 are large, and proteid granules are massed round the lumen, tin- hom<n:> 

 outer zones of the cells being largely composed of glycogen which WHS \ 



in considerable abundance. The outer zones contained numerous fat i: lobules, 

 shewn as dark dots; but us stated in the text these fat globules vary much. 



B. Cells poor in glycogen. Taken from a winter frog which hud U--n kept 

 at22C. for 10 days. The cells contain very little dye.^en and the i 

 grannies are dispersed throughout the cell. In a summer frog well fed on pro- 

 teids the cells would present a very similar apix-anu 



C. Starved cells. Taken from a summer fr.- .ut. -r a 1 >n- fast 



are small and almost free from glycogen. The pmUiid granules are dispersed 

 throughout the cell. 



All the specimens were hardened in 1 p.c. osmic acid, and are drawn to the 

 same or nearly to the same scale. 



