CHAP, iv.] METABOLIC PROCESSES OF THE BODY. 755 



FIG. 93. SECTION OF MAM- 

 MALIAN LIVER RICH IN GLYCO- 

 GEN. (Langley.) 



Osmic acid specimen, gly- 



the hepatic cells (Fig. 93) are large (so large that they have by 

 some authors been described as compressing the lobular capillaries) 

 and loaded with the same refractive hyaline material staining 

 port-wine red with iodine. When this 

 material is dissolved out a coarse open 

 network of cell-substance is displayed. 

 The most marked point of difference be- 

 tween the mammalian and frog's hepatic 

 cell under these conditions is that in the 

 former, the hyaline, glycogenic substance 

 is gathered at first centrally round the 

 nucleus (not more on the outer side as is 

 the case in the frog) and spreads from 

 the centre towards the periphery, always 

 leaving on the extreme outside a some- 

 what thick shell of cell-substance, which 

 in hardened and prepared specimens may vBimo auiu B1(OT1I110U , 

 strikingly simulate a thickened cell-wall, cogen not dissolved out. 

 We may add that in an animal thus fed 

 the whole liver is very large and as it were swollen ; it is also soft 

 and tears easily. 



In an animal fed on proteids alone, for instance on fibrin, 

 the liver frequently contains some gly cogen and the hepatic cells 

 contain a small quantity of hyaline glycogenic material. As in the 

 corresponding case in the frog, the cells are comparatively small, 

 and the cell-substance appears finely and uniformly granular. 



In a starved mammal, the liver is small, dense to the touch 

 and tough; it contains a trace only of 

 glycogen or none at all; the cells (Fig. 

 94) are small, as it were shrunken, and 

 the cell-substance, which gives no port- 

 wine reaction, or a mere trace only, with 

 iodine, is still more finely granular. 



459. The microscopic appearances 

 just described shew, and indeed general 

 considerations lead us to the same con- 

 clusion, that the processes taking place 

 in a hepatic cell are very complex. In 

 the first place the constituents of bile 

 are being formed and discharged into 

 the bile passages after the fashion of 

 an ordinary secreting gland. In the 



second place, a formation of glycogen is servedTn "some "of the cells, 

 also taking pla'ce, and we shall have 



presently to consider briefly the relations of the one process to 

 the other. In the third place, as is especially indicated by the 

 somewhat peculiar effects on the hepatic cell of food exclusively 

 proteid in nature, other processes, analogous perhaps to the form- 



FIG. 94. SECTION OF MAM- 

 MALIAN LIVER, CONTAINING 



LITTLE OR NO GLYCOGEN. 



(Langley.) 



Osmic acid specimen. The 

 granules are not well pre- 



