PRODUCTION OF SUGAR IN THE LITER. 319 



opaline appearance. It is neutral, without odor or taste, 

 and presents nothing characteristic under the microscope. It 

 reacts strongly with iodine, which produces a dark-violet or 

 chestnut-brown color, but rarely a well-marked blue. It 

 presents none of the reactions of sugar, and is entirely in- 

 soluble in alcohol. 1 It is changed into sugar by boiling for 

 a long time with dilute acids, and this conversion is rapidly 

 effected by the saliva, the pancreatic juice, and a- peculiar 

 ferment found in the substance of the liver. Prepared in 

 the way above indicated, and pulverized, it may be preserved 

 for an indefinite period. 



The peculiar reaction of the glycogenic matter with 

 iodine has led to its recognition in the substance of the liver- 

 cells and in some other situations. Schiff found in the 

 liver-cells minute granulations, which presented the peculiar 

 color on the addition of iodine, characteristic of glycogenic 

 matter. 3 Bernard, a few years after his discovery of this 

 principle in the liver, recognized it in cells attached to the 

 placenta. He believes that these cells produce sugar during 

 the early period of foetal life, before the liver takes on this 

 function, and that they disappear during the later months, as 

 the liver becomes fully developed. 3 



Since the discovery of the glycogenic function of the 

 liver, anatomists have found amyloid corpuscles in various 

 of the tissues of the body. We do not propose, however, to 

 discuss this question in all its bearings, but only to consider 

 the known relations of the amyloid substances found in the 

 body to the formation of sugar. 



In the first place, there can be no doubt of the fact, that 

 the liver of a carnivorous animal that has been fed exclu- 

 sively on meat contains an amyloid substance readily con- 



1 BERNARD, Lemons sur la physiologic et la pathologic dit systeme nerveux, Paris, 

 1858, tome i., p. 4tO. 



2 SCHIFF, De la nature des granulations qui remplissent les cellules hepatiques : 

 Amidon animak. Comptes rendm, Paris, 1859, tome xlviii., p. 880. 



3 BERNARD, Sur une nouvdle fonction du placenta. Journal de la physiologic, 

 Paris, 1859, tome ii., p. 31, et seq. 



