314 SCIENCE PROGRESS. 



estimated by Briicke's method. It was found that in the 

 first half-hour the disappearance of glycogen was very rapid; 

 it then slowly and steadily diminished for a few hours 

 afterwards. 



If, however, the liver substance is destroyed by grinding 

 it up with sand, the loss of glycogen is inconsiderable when 

 compared with control specimens, in which the liver was 

 simply roughly minced and in which the cells would there- 

 fore retain their integrity. 



Microscopic examination of the liver cells in salt solu- 

 tion shows that they undergo certain degenerative changes 

 which usually begin within the first hour. 



The conversion of glycogen is, therefore, divided into 

 two periods. 



(i) An early period of rapid conversion occurring before 

 obvious structural changes occur in the liver cells. 



(2) A late period of slow conversion after these changes 

 have developed. 



The first rapid change is inhibited by destroying the 

 liver cells by a temperature of over 6o° and by one per 

 cent, solutions of sodium fluoride. It is regarded as bein<>' 

 produced by the action of the living liver cells. The second 

 slower change is apparently not affected by these agencies, 

 and is regarded as being due to the activity of an enzyme. 



Chloroform was found to increase hepatic amylolysis, 

 and to accelerate the structural changes in the liver cells ; it 

 acts probably by stimulating the katabolic changes in the 

 cells which precede their death. Chloroform would appear to 

 act in the same way during life ; glycosuria is by no means, 

 an infrequent accompaniment of chloroform narcosis, and in 

 pairs of animals of the same litter, one chloroformed, the 

 other not, the hepatic glycogen was always found to be 

 more abundant in the latter case. Ether acts in the same 

 way as chloroform, only to a less degree. Pyrogallic acid (0*25 

 per cent, solution) acts similarly. Morphine, curare, amy] 

 nitrite and sodium salicylate have no action. 



The products of hepatic amylolysis were also investi- 

 gated. In the early stage glucose appears to be formed 

 directly, and no intermediate substances, such as dextrins 



