ABSORPTION. 205 



PRODUCTION OF GLYCOGEN, IN DOGS, UNDER VARYING DIET. 



Diet for Weight of liver, Glycogen in the 



several days in percentage of fresh liver, 



previously. bodily weight. per cent. 



Tripe 3.03 7.19 



Tripe and sugar .... 6.42 14.50 



Meal, bread, potatoes . . . 6.06 17.23 



Experiments on the rabbit also showed that in this animal both the 

 weight of the liver and its percentage in glycogen are much diminished 

 by fasting, but are maintained at the maximum standard, for a time at 

 least, by an exclusive diet of carbohydrates. The average results were 

 as follow- : 



AVEIJAGE PRODUCTION OF GLTCOGEN IN RABBITS, WHEN FASTING AND WHEN 

 FED ON CARBOHYDRATES. 



Diet for three Absolute weight of Glycogen in the fresh 



days previously. liver (grammes . liver (per cent). 



No food 34.02 1.35 



Starch and sugar . . . 73.71 16.15 



The quantity of glycogen found in the liver by Pavy is greater than 

 that obtained by subsequent observers under similar circumstances ; but 

 the fact of the increase of glycogen under the use of carbohydrates has 

 been confirmed by other experimenters. Dock * found, in experiments 

 on the rabbit, that after from 3 to 5 days' fasting the glycogen in the 

 liver was reduced to a very minute quantity, or more frequently was 

 entirely absent. But if, in this condition, a solution of glucose were 

 introduced into the stomach through a catheter, and the animal killed 

 from 19 to 24 hours afterward, the glycogen in the liver amounted to 

 from 0.650 to 1.243 grammes. After even 7 days' fasting, followed by 

 an injection of glucose into the stomach, so short a time as four hours 

 w r as sufficient to produce an abundance of glycogen in the liver. The 

 deposit of this substance accordingly takes place so rapidly after the 

 ingestion of this kind of food, that no doubt can remain of its being 

 produced from saccharine or starchy substances. 



Tscherinow ( showed, by his observations on fo\vls, both the produc- 

 tion of glycogen from animal food, and its more abundant deposit under 

 a vegetable diet. He found, in this species, two days' fasting sufficient 

 to reduce the glycogen to a minimum. After a preliminary fast of this 

 duration, the fowls were fed for two or three days with different kinds of 

 food, and then killed and examined. The average results w r ere as follows : 



PRODUCTION OF GLYCOGEN IN FOWLS UNDER DIFFERENT KINDS OF DIET. 

 Diet previous to the Glycogen in the fre^h 



experiment. liver, per cent. 



Fasting, 2 days 0.57 



Lean meat, 2 to 4 days 1.40 



Barley, 2 days 5.41 



Pace, 2 days 7.21 



Fibrine* and sugar, 2 to 3 days 10.20 



* Archiv fur die gesammte Physiologic. Bonn, 1872, Band v., p. 571. 

 f Archiv fur pathologische Anatomic und Physiologic. Berlin, 1869, Band 

 xlvii., p. 102. 



